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freebsd-nq/lib/libarchive/archive_read_support_format_tar.c
Tim Kientzle 9e21a48274 In GNU tar archives, read ctime from ctime field, not atime field. 
Credit: Juergen Lock
2004-04-20 20:09:06 +00:00

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/*-
* Copyright (c) 2003-2004 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD$");
#include <sys/stat.h>
#include <errno.h>
/* #include <stdint.h> */ /* See archive_platform.h */
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "archive.h"
#include "archive_entry.h"
#include "archive_private.h"
/*
* Layout of POSIX 'ustar' tar header.
*/
struct archive_entry_header_ustar {
char name[100];
char mode[8];
char uid[8];
char gid[8];
char size[12];
char mtime[12];
char checksum[8];
char typeflag[1];
char linkname[100]; /* "old format" header ends here */
char magic[6]; /* For POSIX: "ustar\0" */
char version[2]; /* For POSIX: "00" */
char uname[32];
char gname[32];
char devmajor[8];
char devminor[8];
char prefix[155];
};
/*
* Data specific to this format.
*/
struct tar {
struct archive_string acl_text;
struct archive_string entry_name;
struct archive_string entry_linkname;
struct archive_string entry_uname;
struct archive_string entry_gname;
struct archive_string longlink;
struct archive_string longname;
struct archive_string pax_header;
struct archive_string pax_global;
wchar_t *pax_entry;
size_t pax_entry_length;
int header_recursion_depth;
};
static size_t UTF8_mbrtowc(wchar_t *pwc, const char *s, size_t n);
static int archive_block_is_null(const unsigned char *p);
static int header_Solaris_ACL(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *);
static int header_common(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *);
static int header_old_tar(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *);
static int header_pax_extensions(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *);
static int header_pax_global(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *h);
static int header_longlink(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *h);
static int header_longname(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *h);
static int header_volume(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *h);
static int header_ustar(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *h);
static int header_gnutar(struct archive *, struct tar *,
struct archive_entry *, struct stat *, const void *h);
static int archive_read_format_tar_bid(struct archive *);
static int archive_read_format_tar_cleanup(struct archive *);
static int archive_read_format_tar_read_header(struct archive *,
struct archive_entry *);
static int checksum(struct archive *, const void *);
static int pax_attribute(struct archive_entry *, struct stat *,
wchar_t *key, wchar_t *value);
static int pax_header(struct archive *, struct tar *,
struct archive_entry *, struct stat *, char *attr);
static void pax_time(const wchar_t *, struct timespec *t);
static int read_body_to_string(struct archive *, struct archive_string *,
const void *h);
static int64_t tar_atol(const char *, unsigned);
static int64_t tar_atol10(const wchar_t *, unsigned);
static int64_t tar_atol256(const char *, unsigned);
static int64_t tar_atol8(const char *, unsigned);
static int tar_read_header(struct archive *, struct tar *,
struct archive_entry *, struct stat *);
static int utf8_decode(wchar_t *, const char *, size_t length);
int
archive_read_support_format_gnutar(struct archive *a)
{
return (archive_read_support_format_tar(a));
}
int
archive_read_support_format_tar(struct archive *a)
{
struct tar *tar;
int r;
tar = malloc(sizeof(*tar));
memset(tar, 0, sizeof(*tar));
r = __archive_read_register_format(a, tar,
archive_read_format_tar_bid,
archive_read_format_tar_read_header,
archive_read_format_tar_cleanup);
if (r != ARCHIVE_OK)
free(tar);
return (ARCHIVE_OK);
}
static int
archive_read_format_tar_cleanup(struct archive *a)
{
struct tar *tar;
tar = *(a->pformat_data);
archive_string_free(&tar->acl_text);
archive_string_free(&tar->entry_name);
archive_string_free(&tar->entry_linkname);
archive_string_free(&tar->entry_uname);
archive_string_free(&tar->entry_gname);
archive_string_free(&tar->pax_global);
archive_string_free(&tar->pax_header);
if (tar->pax_entry != NULL)
free(tar->pax_entry);
free(tar);
*(a->pformat_data) = NULL;
return (ARCHIVE_OK);
}
static int
archive_read_format_tar_bid(struct archive *a)
{
int bid;
ssize_t bytes_read;
const void *h;
const struct archive_entry_header_ustar *header;
/*
* If we're already reading a non-tar file, don't
* bother to bid.
*/
if (a->archive_format != 0 &&
(a->archive_format & ARCHIVE_FORMAT_BASE_MASK) !=
ARCHIVE_FORMAT_TAR)
return (0);
bid = 0;
/*
* If we're already reading a tar format, start the bid at 1 as
* a failsafe.
*/
if ((a->archive_format & ARCHIVE_FORMAT_BASE_MASK) ==
ARCHIVE_FORMAT_TAR)
bid++;
/* Now let's look at the actual header and see if it matches. */
bytes_read = (a->compression_read_ahead)(a, &h, 512);
if (bytes_read < 512)
return (ARCHIVE_FATAL);
/* If it's an end-of-archive mark, we can handle it. */
if ((*(const char *)h) == 0 && archive_block_is_null(h))
return (bid + 1);
/* If it's not an end-of-archive mark, it must have a valid checksum.*/
if (!checksum(a, h))
return (0);
bid += 48; /* Checksum is usually 6 octal digits. */
header = h;
/* This distinguishes POSIX formats from GNU tar formats. */
if ((memcmp(header->magic, "ustar\0", 6) == 0)
&&(memcmp(header->version, "00", 2)==0))
bid += 56;
/* Recognize GNU tar format as well. */
if ((memcmp(header->magic, "ustar ", 6) == 0)
&&(memcmp(header->version, " \0", 2)==0))
bid += 56;
/* Type flag must be null, digit or A-Z, a-z. */
if (header->typeflag[0] != 0 &&
!( header->typeflag[0] >= '0' && header->typeflag[0] <= '9') &&
!( header->typeflag[0] >= 'A' && header->typeflag[0] <= 'Z') &&
!( header->typeflag[0] >= 'a' && header->typeflag[0] <= 'z') )
return (0);
/* Sanity check: Look at first byte of mode field. */
switch (255 & (unsigned)header->mode[0]) {
case 0: case 255:
/* Base-256 value: No further verification possible! */
break;
case ' ': /* Not recommended, but not illegal, either. */
break;
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
/* Octal Value. */
/* TODO: Check format of remainder of this field. */
break;
default:
/* Not a valid mode; bail out here. */
return (0);
}
/* TODO: Sanity test uid/gid/size/mtime/devmajor/devminor fields. */
return (bid);
}
/*
* The function invoked by archive_read_header(). This
* just sets up a few things and then calls the internal
* tar_read_header() function below.
*/
static int
archive_read_format_tar_read_header(struct archive *a,
struct archive_entry *entry)
{
struct stat st;
struct tar *tar;
memset(&st, 0, sizeof(st));
tar = *(a->pformat_data);
return (tar_read_header(a, tar, entry, &st));
}
/*
* This function recursively interprets all of the headers associated
* with a single entry.
*/
static int
tar_read_header(struct archive *a, struct tar *tar,
struct archive_entry *entry, struct stat *st)
{
ssize_t bytes;
int err;
const void *h;
const struct archive_entry_header_ustar *header;
/* Read 512-byte header record */
bytes = (a->compression_read_ahead)(a, &h, 512);
if (bytes < 512) {
/* TODO: Set error values */
return (-1);
}
(a->compression_read_consume)(a, 512);
/* Check for end-of-archive mark. */
if (((*(const char *)h)==0) && archive_block_is_null(h)) {
archive_set_error(a, 0, NULL);
return (ARCHIVE_EOF);
}
/*
* Note: If the checksum fails and we return ARCHIVE_RETRY,
* then the client is likely to just retry. This is a very
* crude way to search for the next valid header!
*
* TODO: Improve this by implementing a real header scan.
*/
if (!checksum(a, h)) {
archive_set_error(a, EINVAL, "Damaged tar archive");
return (ARCHIVE_RETRY); /* Retryable: Invalid header */
}
if (++tar->header_recursion_depth > 32) {
archive_set_error(a, EINVAL, "Too many special headers");
return (ARCHIVE_WARN);
}
/* Determine the format variant. */
header = h;
switch(header->typeflag[0]) {
case 'A': /* Solaris tar ACL */
a->archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
a->archive_format_name = "Solaris tar";
err = header_Solaris_ACL(a, tar, entry, st, h);
break;
case 'g': /* POSIX-standard 'g' header. */
a->archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
a->archive_format_name = "POSIX pax interchange format";
err = header_pax_global(a, tar, entry, st, h);
break;
case 'K': /* Long link name (GNU tar, others) */
err = header_longlink(a, tar, entry, st, h);
break;
case 'L': /* Long filename (GNU tar, others) */
err = header_longname(a, tar, entry, st, h);
break;
case 'V': /* GNU volume header */
err = header_volume(a, tar, entry, st, h);
break;
case 'X': /* Used by SUN tar; same as 'x'. */
a->archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
a->archive_format_name =
"POSIX pax interchange format (Sun variant)";
err = header_pax_extensions(a, tar, entry, st, h);
break;
case 'x': /* POSIX-standard 'x' header. */
a->archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
a->archive_format_name = "POSIX pax interchange format";
err = header_pax_extensions(a, tar, entry, st, h);
break;
default:
if (memcmp(header->magic, "ustar \0", 8) == 0) {
a->archive_format = ARCHIVE_FORMAT_TAR_GNUTAR;
a->archive_format_name = "GNU tar format";
err = header_gnutar(a, tar, entry, st, h);
} else if (memcmp(header->magic, "ustar", 5) == 0) {
if (a->archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE) {
a->archive_format = ARCHIVE_FORMAT_TAR_USTAR;
a->archive_format_name = "POSIX ustar format";
}
err = header_ustar(a, tar, entry, st, h);
} else {
a->archive_format = ARCHIVE_FORMAT_TAR;
a->archive_format_name = "tar (non-POSIX)";
err = header_old_tar(a, tar, entry, st, h);
}
}
archive_entry_copy_stat(entry, st);
--tar->header_recursion_depth;
return (err);
}
/*
* Return true if block checksum is correct.
*/
static int
checksum(struct archive *a, const void *h)
{
const unsigned char *bytes;
const struct archive_entry_header_ustar *header;
int check, i, sum;
(void)a; /* UNUSED */
bytes = h;
header = h;
/*
* Test the checksum. Note that POSIX specifies _unsigned_
* bytes for this calculation.
*/
sum = tar_atol(header->checksum, sizeof(header->checksum));
check = 0;
for (i = 0; i < 148; i++)
check += (unsigned char)bytes[i];
for (; i < 156; i++)
check += 32;
for (; i < 512; i++)
check += (unsigned char)bytes[i];
if (sum == check)
return (1);
/*
* Repeat test with _signed_ bytes, just in case this archive
* was created by an old BSD, Solaris, or HP-UX tar with a
* broken checksum calculation.
*/
check = 0;
for (i = 0; i < 148; i++)
check += (signed char)bytes[i];
for (; i < 156; i++)
check += 32;
for (; i < 512; i++)
check += (signed char)bytes[i];
if (sum == check)
return (1);
return (0);
}
/*
* Return true if this block contains only nulls.
*/
static int
archive_block_is_null(const unsigned char *p)
{
unsigned i;
for (i = 0; i < ARCHIVE_BYTES_PER_RECORD / sizeof(*p); i++)
if (*p++)
return (0);
return (1);
}
/*
* Interpret 'A' Solaris ACL header
*/
static int
header_Solaris_ACL(struct archive *a, struct tar *tar,
struct archive_entry *entry, struct stat *st, const void *h)
{
int err, err2;
char *p;
wchar_t *wp;
err = read_body_to_string(a, &(tar->acl_text), h);
err2 = tar_read_header(a, tar, entry, st);
err = err_combine(err, err2);
/* XXX Ensure p doesn't overrun acl_text */
/* Skip leading octal number. */
/* XXX TODO: Parse the octal number and sanity-check it. */
p = tar->acl_text.s;
while (*p != '\0')
p++;
p++;
wp = malloc((strlen(p) + 1) * sizeof(wchar_t));
if (wp != NULL) {
utf8_decode(wp, p, strlen(p));
err2 = __archive_entry_acl_parse_w(entry, wp,
ARCHIVE_ENTRY_ACL_TYPE_ACCESS);
err = err_combine(err, err2);
free(wp);
}
return (err);
}
/*
* Interpret 'K' long linkname header.
*/
static int
header_longlink(struct archive *a, struct tar *tar,
struct archive_entry *entry, struct stat *st, const void *h)
{
int err, err2;
err = read_body_to_string(a, &(tar->longlink), h);
err2 = tar_read_header(a, tar, entry, st);
if (err == ARCHIVE_OK && err2 == ARCHIVE_OK) {
/* Set symlink if symlink already set, else hardlink. */
archive_entry_set_link(entry, tar->longlink.s);
}
return (err_combine(err, err2));
}
/*
* Interpret 'L' long filename header.
*/
static int
header_longname(struct archive *a, struct tar *tar,
struct archive_entry *entry, struct stat *st, const void *h)
{
int err, err2;
err = read_body_to_string(a, &(tar->longname), h);
/* Read and parse "real" header, then override name. */
err2 = tar_read_header(a, tar, entry, st);
if (err == ARCHIVE_OK && err2 == ARCHIVE_OK)
archive_entry_set_pathname(entry, tar->longname.s);
return (err_combine(err, err2));
}
/*
* Interpret 'V' GNU tar volume header.
*/
static int
header_volume(struct archive *a, struct tar *tar,
struct archive_entry *entry, struct stat *st, const void *h)
{
(void)h;
/* Just skip this and read the next header. */
return (tar_read_header(a, tar, entry, st));
}
/*
* Read body of an archive entry into an archive_string object.
*/
static int
read_body_to_string(struct archive *a, struct archive_string *as, const void *h)
{
const struct archive_entry_header_ustar *header;
off_t size;
unsigned oldstate;
int err, err2;
header = h;
size = tar_atol(header->size, sizeof(header->size));
/* Temporarily fudge internal state for read_data call. */
oldstate = a->state;
a->state = ARCHIVE_STATE_DATA;
/* Read the body into the string. */
a->entry_bytes_remaining = size;
a->entry_padding = 0x1ff & -size;
archive_string_ensure(as, size+1);
err = archive_read_data_into_buffer(a, as->s, size);
as->s[size] = 0; /* Null terminate name! */
err2 = archive_read_data_skip(a); /* Resync for next header. */
/* Restore the state. */
a->state = oldstate;
return (err_combine(err, err2));
}
/*
* Parse out common header elements.
*
* This would be the same as header_old_tar, except that the
* filename is handled slightly differently for old and POSIX
* entries (POSIX entries support a 'prefix'). This factoring
* allows header_old_tar and header_ustar
* to handle filenames differently, while still putting most of the
* common parsing into one place.
*/
static int
header_common(struct archive *a, struct tar *tar, struct archive_entry *entry,
struct stat *st, const void *h)
{
const struct archive_entry_header_ustar *header;
char tartype;
(void)a; /* UNUSED */
header = h;
if (header->linkname[0])
archive_strncpy(&(tar->entry_linkname), header->linkname,
sizeof(header->linkname));
else
archive_string_empty(&(tar->entry_linkname));
/* Parse out the numeric fields (all are octal) */
st->st_mode = tar_atol(header->mode, sizeof(header->mode));
st->st_uid = tar_atol(header->uid, sizeof(header->uid));
st->st_gid = tar_atol(header->gid, sizeof(header->gid));
st->st_size = tar_atol(header->size, sizeof(header->size));
st->st_mtime = tar_atol(header->mtime, sizeof(header->mtime));
/* Handle the tar type flag appropriately. */
tartype = header->typeflag[0];
st->st_mode &= ~S_IFMT;
switch (tartype) {
case '1': /* Hard link */
archive_entry_set_hardlink(entry, tar->entry_linkname.s);
/*
* The following may seem odd, but: Technically, tar
* does not store the file type for a "hard link"
* entry, only the fact that it is a hard link. So, I
* leave the type zero normally. But, pax interchange
* format allows hard links to have data, which
* implies that the underlying entry is a regular
* file.
*/
if (st->st_size > 0)
st->st_mode |= S_IFREG;
break;
case '2': /* Symlink */
st->st_mode |= S_IFLNK;
st->st_size = 0;
archive_entry_set_symlink(entry, tar->entry_linkname.s);
break;
case '3': /* Character device */
st->st_mode |= S_IFCHR;
st->st_size = 0;
break;
case '4': /* Block device */
st->st_mode |= S_IFBLK;
st->st_size = 0;
break;
case '5': /* Dir */
st->st_mode |= S_IFDIR;
st->st_size = 0;
break;
case '6': /* FIFO device */
st->st_mode |= S_IFIFO;
st->st_size = 0;
break;
case 'D': /* GNU incremental directory type */
/*
* No special handling is actually required here.
* It might be nice someday to preprocess the file list and
* provide it to the client, though.
*/
st->st_mode |= S_IFDIR;
break;
case 'M': /* GNU "Multi-volume" (remainder of file from last archive)*/
/*
* As far as I can tell, this is just like a regular file
* entry, except that the contents should be _appended_ to
* the indicated file at the indicated offset. This may
* require some API work to fully support.
*/
break;
case 'N': /* Old GNU "long filename" entry. */
/* The body of this entry is a script for renaming
* previously-extracted entries. Ugh. It will never
* be supported by libarchive. */
st->st_mode |= S_IFREG;
break;
case 'S': /* GNU sparse files */
/* I would like to support these someday... */
break;
default: /* Regular file and non-standard types */
/*
* Per POSIX: non-recognized types should always be
* treated as regular files.
*/
st->st_mode |= S_IFREG;
break;
}
return (0);
}
/*
* Parse out header elements for "old-style" tar archives.
*/
static int
header_old_tar(struct archive *a, struct tar *tar, struct archive_entry *entry,
struct stat *st, const void *h)
{
const struct archive_entry_header_ustar *header;
/* Copy filename over (to ensure null termination). */
header = h;
archive_strncpy(&(tar->entry_name), header->name, sizeof(header->name));
archive_entry_set_pathname(entry, tar->entry_name.s);
/* Grab rest of common fields */
header_common(a, tar, entry, st, h);
/*
* TODO: Decide whether the following special handling
* is needed for POSIX headers. Factor accordingly.
*/
/* "Regular" entry with trailing '/' is really directory. */
if (S_ISREG(st->st_mode) &&
'/' == tar->entry_name.s[strlen(tar->entry_name.s) - 1]) {
st->st_mode &= ~S_IFMT;
st->st_mode |= S_IFDIR;
}
a->entry_bytes_remaining = st->st_size;
a->entry_padding = 0x1ff & (-a->entry_bytes_remaining);
return (0);
}
/*
* Parse a file header for a pax extended archive entry.
*/
static int
header_pax_global(struct archive *a, struct tar *tar,
struct archive_entry *entry, struct stat *st, const void *h)
{
int err, err2;
err = read_body_to_string(a, &(tar->pax_global), h);
err2 = tar_read_header(a, tar, entry, st);
return (err_combine(err, err2));
}
static int
header_pax_extensions(struct archive *a, struct tar *tar,
struct archive_entry *entry, struct stat *st, const void *h)
{
int err, err2;
read_body_to_string(a, &(tar->pax_header), h);
/* Parse the next header. */
err = tar_read_header(a, tar, entry, st);
/*
* TODO: Parse global/default options into 'entry' struct here
* before handling file-specific options.
*
* This design (parse standard header, then overwrite with pax
* extended attribute data) usually works well, but isn't ideal;
* it would be better to parse the pax extended attributes first
* and then skip any fields in the standard header that were
* defined in the pax header.
*/
err2 = pax_header(a, tar, entry, st, tar->pax_header.s);
err = err_combine(err, err2);
a->entry_bytes_remaining = st->st_size;
a->entry_padding = 0x1ff & (-a->entry_bytes_remaining);
return (err);
}
/*
* Parse a file header for a Posix "ustar" archive entry. This also
* handles "pax" or "extended ustar" entries.
*/
static int
header_ustar(struct archive *a, struct tar *tar, struct archive_entry *entry,
struct stat *st, const void *h)
{
const struct archive_entry_header_ustar *header;
header = h;
/* Copy name into an internal buffer to ensure null-termination. */
if (header->prefix[0]) {
archive_strncpy(&(tar->entry_name), header->prefix,
sizeof(header->prefix));
archive_strappend_char(&(tar->entry_name), '/');
archive_strncat(&(tar->entry_name), header->name,
sizeof(header->name));
} else
archive_strncpy(&(tar->entry_name), header->name,
sizeof(header->name));
archive_entry_set_pathname(entry, tar->entry_name.s);
/* Handle rest of common fields. */
header_common(a, tar, entry, st, h);
/* Handle POSIX ustar fields. */
archive_strncpy(&(tar->entry_uname), header->uname,
sizeof(header->uname));
archive_entry_set_uname(entry, tar->entry_uname.s);
archive_strncpy(&(tar->entry_gname), header->gname,
sizeof(header->gname));
archive_entry_set_gname(entry, tar->entry_gname.s);
/* Parse out device numbers only for char and block specials. */
if (header->typeflag[0] == '3' || header->typeflag[0] == '4') {
st->st_rdev = makedev(
tar_atol(header->devmajor, sizeof(header->devmajor)),
tar_atol(header->devminor, sizeof(header->devminor)));
}
a->entry_bytes_remaining = st->st_size;
a->entry_padding = 0x1ff & (-a->entry_bytes_remaining);
return (0);
}
/*
* Parse the pax extended attributes record.
*
* Returns non-zero if there's an error in the data.
*/
static int
pax_header(struct archive *a, struct tar *tar, struct archive_entry *entry,
struct stat *st, char *attr)
{
size_t attr_length, l, line_length;
char *line, *p;
wchar_t *key, *wp, *value;
int err, err2;
attr_length = strlen(attr);
err = ARCHIVE_OK;
while (attr_length > 0) {
/* Parse decimal length field at start of line. */
line_length = 0;
l = attr_length;
line = p = attr; /* Record start of line. */
while (l>0) {
if (*p == ' ') {
p++;
l--;
break;
}
if (*p < '0' || *p > '9')
return (-1);
line_length *= 10;
line_length += *p - '0';
if (line_length > 999999)
return (-1);
p++;
l--;
}
if (line_length > attr_length)
return (0);
/* Ensure pax_entry buffer is big enough. */
if (tar->pax_entry_length <= line_length) {
if (tar->pax_entry_length <= 0)
tar->pax_entry_length = 1024;
while (tar->pax_entry_length <= line_length + 1)
tar->pax_entry_length *= 2;
/* XXX Error handling here */
tar->pax_entry = realloc(tar->pax_entry,
tar->pax_entry_length * sizeof(wchar_t));
}
/* Decode UTF-8 to wchar_t, null-terminate result. */
if (utf8_decode(tar->pax_entry, p,
line_length - (p - attr) - 1)) {
archive_set_error(a, ARCHIVE_ERRNO_MISC,
"Invalid UTF8 character in pax extended attribute");
err = err_combine(err, ARCHIVE_WARN);
}
/* Null-terminate 'key' value. */
key = tar->pax_entry;
if (key[0] == L'=')
return (-1);
wp = wcschr(key, L'=');
if (wp == NULL) {
archive_set_error(a, ARCHIVE_ERRNO_MISC,
"Invalid pax extended attributes");
return (ARCHIVE_WARN);
}
*wp = 0;
/* Identify null-terminated 'value' portion. */
value = wp + 1;
/* Identify this attribute and set it in the entry. */
err2 = pax_attribute(entry, st, key, value);
err = err_combine(err, err2);
/* Skip to next line */
attr += line_length;
attr_length -= line_length;
}
return (err);
}
/*
* Parse a single key=value attribute. key/value pointers are
* assumed to point into reasonably long-lived storage.
*
* Note that POSIX reserves all-lowercase keywords. Vendor-specific
* extensions should always have keywords of the form "VENDOR.attribute"
* In particular, it's quite feasible to support many different
* vendor extensions here. I'm using "LIBARCHIVE" for extensions
* unique to this library (currently, there are none).
*
* Investigate other vendor-specific extensions, as well and see if
* any of them look useful.
*/
static int
pax_attribute(struct archive_entry *entry, struct stat *st,
wchar_t *key, wchar_t *value)
{
switch (key[0]) {
case 'L':
/* Our extensions */
/* TODO: Handle arbitrary extended attributes... */
/*
if (strcmp(key, "LIBARCHIVE.xxxxxxx")==0)
archive_entry_set_xxxxxx(entry, value);
*/
break;
case 'S':
/* We support some keys used by the "star" archiver */
if (wcscmp(key, L"SCHILY.acl.access")==0)
__archive_entry_acl_parse_w(entry, value,
ARCHIVE_ENTRY_ACL_TYPE_ACCESS);
else if (wcscmp(key, L"SCHILY.acl.default")==0)
__archive_entry_acl_parse_w(entry, value,
ARCHIVE_ENTRY_ACL_TYPE_DEFAULT);
else if (wcscmp(key, L"SCHILY.devmajor")==0)
st->st_rdev = makedev(tar_atol10(value, wcslen(value)),
minor(st->st_dev));
else if (wcscmp(key, L"SCHILY.devminor")==0)
st->st_rdev = makedev(major(st->st_dev),
tar_atol10(value, wcslen(value)));
else if (wcscmp(key, L"SCHILY.fflags")==0)
archive_entry_copy_fflags_w(entry, value);
else if (wcscmp(key, L"SCHILY.nlink")==0)
st->st_nlink = tar_atol10(value, wcslen(value));
break;
case 'a':
if (wcscmp(key, L"atime")==0)
pax_time(value, &(st->st_atimespec));
break;
case 'c':
if (wcscmp(key, L"ctime")==0)
pax_time(value, &(st->st_ctimespec));
else if (wcscmp(key, L"charset")==0) {
/* TODO: Publish charset information in entry. */
} else if (wcscmp(key, L"comment")==0) {
/* TODO: Publish comment in entry. */
}
break;
case 'g':
if (wcscmp(key, L"gid")==0)
st->st_gid = tar_atol10(value, wcslen(value));
else if (wcscmp(key, L"gname")==0)
archive_entry_copy_gname_w(entry, value);
break;
case 'l':
/* pax interchange doesn't distinguish hardlink vs. symlink. */
if (wcscmp(key, L"linkpath")==0) {
if (archive_entry_hardlink(entry))
archive_entry_copy_hardlink_w(entry, value);
else
archive_entry_copy_symlink_w(entry, value);
}
break;
case 'm':
if (wcscmp(key, L"mtime")==0)
pax_time(value, &(st->st_mtimespec));
break;
case 'p':
if (wcscmp(key, L"path")==0)
archive_entry_copy_pathname_w(entry, value);
break;
case 'r':
/* POSIX has reserved 'realtime.*' */
break;
case 's':
/* POSIX has reserved 'security.*' */
/* Someday: if (wcscmp(key, L"security.acl")==0) { ... } */
if (wcscmp(key, L"size")==0)
st->st_size = tar_atol10(value, wcslen(value));
break;
case 'u':
if (wcscmp(key, L"uid")==0)
st->st_uid = tar_atol10(value, wcslen(value));
else if (wcscmp(key, L"uname")==0)
archive_entry_copy_uname_w(entry, value);
break;
}
return (0);
}
/*
* parse a decimal time value, which may include a fractional portion
*/
static void
pax_time(const wchar_t *p, struct timespec *t)
{
char digit;
int64_t s;
unsigned long l;
int sign;
static const int64_t limit64 = INT64_MAX / 10;
static const char last_digit_limit64 = INT64_MAX % 10;
s = 0;
sign = 1;
if (*p == '-') {
sign = -1;
p++;
}
while (*p >= '0' && *p <= '9') {
digit = *p - '0';
if (s > limit64 ||
(s == limit64 && digit > last_digit_limit64)) {
s = UINT64_MAX; /* Truncate on overflow */
break;
}
s = (s * 10) + digit;
++p;
}
t->tv_sec = s * sign;
/* Calculate nanoseconds. */
t->tv_nsec = 0;
if (*p != '.')
return;
l = 100000000UL;
do {
++p;
if (*p >= '0' && *p <= '9')
t->tv_nsec += (*p - '0') * l;
else
break;
} while (l /= 10);
}
/*
* Structure of GNU tar header
*/
struct archive_entry_header_gnutar {
char name[100];
char mode[8];
char uid[8];
char gid[8];
char size[12];
char mtime[12];
char checksum[8];
char typeflag[1];
char linkname[100];
char magic[8]; /* "ustar \0" (note blank/blank/null at end) */
char uname[32];
char gname[32];
char devmajor[8];
char devminor[8];
char atime[12];
char ctime[12];
char offset[12];
char longnames[4];
char unused[1];
struct {
char offset[12];
char numbytes[12];
} sparse[4];
char isextended[1];
char realsize[12];
/*
* GNU doesn't use POSIX 'prefix' field; they use the 'L' (longname)
* entry instead.
*/
};
/*
* Parse GNU tar header
*/
static int
header_gnutar(struct archive *a, struct tar *tar, struct archive_entry *entry,
struct stat *st, const void *h)
{
const struct archive_entry_header_gnutar *header;
(void)a;
/*
* GNU header is like POSIX ustar, except 'prefix' is
* replaced with some other fields. This also means the
* filename is stored as in old-style archives.
*/
/* Grab fields common to all tar variants. */
header_common(a, tar, entry, st, h);
/* Copy filename over (to ensure null termination). */
header = h;
archive_strncpy(&(tar->entry_name), header->name,
sizeof(header->name));
archive_entry_set_pathname(entry, tar->entry_name.s);
/* Fields common to ustar and GNU */
/* XXX Can the following be factored out since it's common
* to ustar and gnu tar? Is it okay to move it down into
* header_common, perhaps? */
archive_strncpy(&(tar->entry_uname),
header->uname, sizeof(header->uname));
archive_entry_set_uname(entry, tar->entry_uname.s);
archive_strncpy(&(tar->entry_gname),
header->gname, sizeof(header->gname));
archive_entry_set_gname(entry, tar->entry_gname.s);
/* Parse out device numbers only for char and block specials */
if (header->typeflag[0] == '3' || header->typeflag[0] == '4')
st->st_rdev = makedev (
tar_atol(header->devmajor, sizeof(header->devmajor)),
tar_atol(header->devminor, sizeof(header->devminor)));
else
st->st_rdev = 0;
/* Grab GNU-specific fields. */
/* TODO: FILL THIS IN!!! */
st->st_atime = tar_atol(header->atime, sizeof(header->atime));
st->st_ctime = tar_atol(header->ctime, sizeof(header->ctime));
/* XXX TODO: Recognize and skip extra GNU header blocks. */
a->entry_bytes_remaining = st->st_size;
a->entry_padding = 0x1ff & (-a->entry_bytes_remaining);
return (0);
}
/*-
* Convert text->integer.
*
* Traditional tar formats (including POSIX) specify base-8 for
* all of the standard numeric fields. This is a significant limitation
* in practice:
* = file size is limited to 8GB
* = devmajor and devminor are limited to 21 bits
* = uid/gid are limited to 21 bits
*
* There are two workarounds for this:
* = pax extended headers, which use variable-length string fields
* = GNU tar and STAR both allow either base-8 or base-256 in
* most fields. The high bit is set to indicate base-256.
*
* On read, this implementation supports both extensions.
*/
static int64_t
tar_atol(const char *p, unsigned char_cnt)
{
if (*p & 0x80)
return (tar_atol256(p, char_cnt));
return (tar_atol8(p, char_cnt));
}
/*
* Note that this implementation does not (and should not!) obey
* locale settings; you cannot simply substitute strtol here, since
* it does obey locale.
*/
static int64_t
tar_atol8(const char *p, unsigned char_cnt)
{
int64_t l;
int digit, sign;
static const int64_t limit = INT64_MAX / 8;
static const int base = 8;
static const char last_digit_limit = INT64_MAX % 8;
while (*p == ' ' || *p == '\t')
p++;
if (*p == '-') {
sign = -1;
p++;
} else
sign = 1;
l = 0;
digit = *p - '0';
while (digit >= 0 && digit < base && char_cnt-- > 0) {
if (l>limit || (l == limit && digit > last_digit_limit)) {
l = UINT64_MAX; /* Truncate on overflow */
break;
}
l = (l * base) + digit;
digit = *++p - '0';
}
return (sign < 0) ? -l : l;
}
/*
* Note that this implementation does not (and should not!) obey
* locale settings; you cannot simply substitute strtol here, since
* it does obey locale.
*/
static int64_t
tar_atol10(const wchar_t *p, unsigned char_cnt)
{
int64_t l;
int digit, sign;
static const int64_t limit = INT64_MAX / 10;
static const int base = 10;
static const char last_digit_limit = INT64_MAX % 10;
while (*p == ' ' || *p == '\t')
p++;
if (*p == '-') {
sign = -1;
p++;
} else
sign = 1;
l = 0;
digit = *p - '0';
while (digit >= 0 && digit < base && char_cnt-- > 0) {
if (l > limit || (l == limit && digit > last_digit_limit)) {
l = UINT64_MAX; /* Truncate on overflow */
break;
}
l = (l * base) + digit;
digit = *++p - '0';
}
return (sign < 0) ? -l : l;
}
/*
* Parse a base-256 integer.
*/
static int64_t
tar_atol256(const char *p, unsigned char_cnt)
{
int64_t l;
int digit;
const int64_t limit = INT64_MAX / 256;
/* Ignore high bit of first byte (that's the base-256 flag). */
l = 0;
digit = 0x7f & *(const unsigned char *)p;
while (char_cnt-- > 0) {
if (l > limit) {
l = INT64_MAX; /* Truncate on overflow */
break;
}
l = (l << 8) + digit;
digit = *(const unsigned char *)++p;
}
return (l);
}
static int
utf8_decode(wchar_t *dest, const char *src, size_t length)
{
size_t n;
int err;
err = 0;
while(length > 0) {
n = UTF8_mbrtowc(dest, src, length);
if (n == 0)
break;
if (n > 8) {
/* Invalid byte encountered; try to keep going. */
*dest = L'?';
n = 1;
err = 1;
}
dest++;
src += n;
length -= n;
}
*dest++ = L'\0';
return (err);
}
/*
* Copied from FreeBSD libc/locale.
*/
static size_t
UTF8_mbrtowc(wchar_t *pwc, const char *s, size_t n)
{
int ch, i, len, mask;
wchar_t lbound, wch;
if (s == NULL)
/* Reset to initial shift state (no-op) */
return (0);
if (n == 0)
/* Incomplete multibyte sequence */
return ((size_t)-2);
/*
* Determine the number of octets that make up this character from
* the first octet, and a mask that extracts the interesting bits of
* the first octet.
*
* We also specify a lower bound for the character code to detect
* redundant, non-"shortest form" encodings. For example, the
* sequence C0 80 is _not_ a legal representation of the null
* character. This enforces a 1-to-1 mapping between character
* codes and their multibyte representations.
*/
ch = (unsigned char)*s;
if ((ch & 0x80) == 0) {
mask = 0x7f;
len = 1;
lbound = 0;
} else if ((ch & 0xe0) == 0xc0) {
mask = 0x1f;
len = 2;
lbound = 0x80;
} else if ((ch & 0xf0) == 0xe0) {
mask = 0x0f;
len = 3;
lbound = 0x800;
} else if ((ch & 0xf8) == 0xf0) {
mask = 0x07;
len = 4;
lbound = 0x10000;
} else if ((ch & 0xfc) == 0xf8) {
mask = 0x03;
len = 5;
lbound = 0x200000;
} else if ((ch & 0xfc) == 0xfc) {
mask = 0x01;
len = 6;
lbound = 0x4000000;
} else {
/*
* Malformed input; input is not UTF-8.
*/
errno = EILSEQ;
return ((size_t)-1);
}
if (n < (size_t)len)
/* Incomplete multibyte sequence */
return ((size_t)-2);
/*
* Decode the octet sequence representing the character in chunks
* of 6 bits, most significant first.
*/
wch = (unsigned char)*s++ & mask;
i = len;
while (--i != 0) {
if ((*s & 0xc0) != 0x80) {
/*
* Malformed input; bad characters in the middle
* of a character.
*/
errno = EILSEQ;
return ((size_t)-1);
}
wch <<= 6;
wch |= *s++ & 0x3f;
}
if (wch < lbound) {
/*
* Malformed input; redundant encoding.
*/
errno = EILSEQ;
return ((size_t)-1);
}
if (pwc != NULL)
*pwc = wch;
return (wch == L'\0' ? 0 : len);
}
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