freebsd-skq/lib/libarchive/archive_write_set_format_pax.c
Tim Kientzle 2228e32755 POSIX.1e-style Extended Attribute support
This commit implements storing/reading POSIX.1e-style extended
attribute information in "pax" format archives.  An outline of the
storage format is in the tar.5 manpage.  The archive_read_extract()
function has code to restore those archives to disk for Linux; FreeBSD
implementation is forthcoming.

Many thanks to Jaakko Heinonen for finding flaws in earlier
proposals and doing the bulk of the coding in this work.
2006-03-21 16:55:46 +00:00

1188 lines
35 KiB
C

/*-
* 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>
#ifdef MAJOR_IN_MKDEV
#include <sys/mkdev.h>
#else
#ifdef MAJOR_IN_SYSMACROS
#include <sys/sysmacros.h>
#endif
#endif
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "archive.h"
#include "archive_entry.h"
#include "archive_private.h"
struct pax {
uint64_t entry_bytes_remaining;
uint64_t entry_padding;
struct archive_string pax_header;
char written;
};
static void add_pax_attr(struct archive_string *, const char *key,
const char *value);
static void add_pax_attr_int(struct archive_string *,
const char *key, int64_t value);
static void add_pax_attr_time(struct archive_string *,
const char *key, int64_t sec,
unsigned long nanos);
static void add_pax_attr_w(struct archive_string *,
const char *key, const wchar_t *wvalue);
static int archive_write_pax_data(struct archive *,
const void *, size_t);
static int archive_write_pax_finish(struct archive *);
static int archive_write_pax_finish_entry(struct archive *);
static int archive_write_pax_header(struct archive *,
struct archive_entry *);
static char *base64_encode(const char *src, size_t len);
static char *build_pax_attribute_name(char *dest, const char *src);
static char *build_ustar_entry_name(char *dest, const char *src,
size_t src_length, const char *insert);
static char *format_int(char *dest, int64_t);
static int has_non_ASCII(const wchar_t *);
static char *url_encode(const char *in);
static int write_nulls(struct archive *, size_t);
/*
* Set output format to 'restricted pax' format.
*
* This is the same as normal 'pax', but tries to suppress
* the pax header whenever possible. This is the default for
* bsdtar, for instance.
*/
int
archive_write_set_format_pax_restricted(struct archive *a)
{
int r;
r = archive_write_set_format_pax(a);
a->archive_format = ARCHIVE_FORMAT_TAR_PAX_RESTRICTED;
a->archive_format_name = "restricted POSIX pax interchange";
return (r);
}
/*
* Set output format to 'pax' format.
*/
int
archive_write_set_format_pax(struct archive *a)
{
struct pax *pax;
if (a->format_finish != NULL)
(a->format_finish)(a);
pax = malloc(sizeof(*pax));
if (pax == NULL) {
archive_set_error(a, ENOMEM, "Can't allocate pax data");
return (ARCHIVE_FATAL);
}
memset(pax, 0, sizeof(*pax));
a->format_data = pax;
a->pad_uncompressed = 1;
a->format_write_header = archive_write_pax_header;
a->format_write_data = archive_write_pax_data;
a->format_finish = archive_write_pax_finish;
a->format_finish_entry = archive_write_pax_finish_entry;
a->archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
a->archive_format_name = "POSIX pax interchange";
return (ARCHIVE_OK);
}
/*
* Note: This code assumes that 'nanos' has the same sign as 'sec',
* which implies that sec=-1, nanos=200000000 represents -1.2 seconds
* and not -0.8 seconds. This is a pretty pedantic point, as we're
* unlikely to encounter many real files created before Jan 1, 1970,
* much less ones with timestamps recorded to sub-second resolution.
*/
static void
add_pax_attr_time(struct archive_string *as, const char *key,
int64_t sec, unsigned long nanos)
{
int digit, i;
char *t;
/*
* Note that each byte contributes fewer than 3 base-10
* digits, so this will always be big enough.
*/
char tmp[1 + 3*sizeof(sec) + 1 + 3*sizeof(nanos)];
tmp[sizeof(tmp) - 1] = 0;
t = tmp + sizeof(tmp) - 1;
/* Skip trailing zeros in the fractional part. */
for (digit = 0, i = 10; i > 0 && digit == 0; i--) {
digit = nanos % 10;
nanos /= 10;
}
/* Only format the fraction if it's non-zero. */
if (i > 0) {
while (i > 0) {
*--t = "0123456789"[digit];
digit = nanos % 10;
nanos /= 10;
i--;
}
*--t = '.';
}
t = format_int(t, sec);
add_pax_attr(as, key, t);
}
static char *
format_int(char *t, int64_t i)
{
int sign;
if (i < 0) {
sign = -1;
i = -i;
} else
sign = 1;
do {
*--t = "0123456789"[i % 10];
} while (i /= 10);
if (sign < 0)
*--t = '-';
return (t);
}
static void
add_pax_attr_int(struct archive_string *as, const char *key, int64_t value)
{
char tmp[1 + 3 * sizeof(value)];
tmp[sizeof(tmp) - 1] = 0;
add_pax_attr(as, key, format_int(tmp + sizeof(tmp) - 1, value));
}
static char *
utf8_encode(const wchar_t *wval)
{
int utf8len;
const wchar_t *wp;
unsigned long wc;
char *utf8_value, *p;
utf8len = 0;
for (wp = wval; *wp != L'\0'; ) {
wc = *wp++;
if (wc <= 0x7f)
utf8len++;
else if (wc <= 0x7ff)
utf8len += 2;
else if (wc <= 0xffff)
utf8len += 3;
else if (wc <= 0x1fffff)
utf8len += 4;
else if (wc <= 0x3ffffff)
utf8len += 5;
else if (wc <= 0x7fffffff)
utf8len += 6;
/* Ignore larger values; UTF-8 can't encode them. */
}
utf8_value = malloc(utf8len + 1);
if (utf8_value == NULL) {
__archive_errx(1, "Not enough memory for attributes");
return (NULL);
}
for (wp = wval, p = utf8_value; *wp != L'\0'; ) {
wc = *wp++;
if (wc <= 0x7f) {
*p++ = (char)wc;
} else if (wc <= 0x7ff) {
p[0] = 0xc0 | ((wc >> 6) & 0x1f);
p[1] = 0x80 | (wc & 0x3f);
p += 2;
} else if (wc <= 0xffff) {
p[0] = 0xe0 | ((wc >> 12) & 0x0f);
p[1] = 0x80 | ((wc >> 6) & 0x3f);
p[2] = 0x80 | (wc & 0x3f);
p += 3;
} else if (wc <= 0x1fffff) {
p[0] = 0xf0 | ((wc >> 18) & 0x07);
p[1] = 0x80 | ((wc >> 12) & 0x3f);
p[2] = 0x80 | ((wc >> 6) & 0x3f);
p[3] = 0x80 | (wc & 0x3f);
p += 4;
} else if (wc <= 0x3ffffff) {
p[0] = 0xf8 | ((wc >> 24) & 0x03);
p[1] = 0x80 | ((wc >> 18) & 0x3f);
p[2] = 0x80 | ((wc >> 12) & 0x3f);
p[3] = 0x80 | ((wc >> 6) & 0x3f);
p[4] = 0x80 | (wc & 0x3f);
p += 5;
} else if (wc <= 0x7fffffff) {
p[0] = 0xfc | ((wc >> 30) & 0x01);
p[1] = 0x80 | ((wc >> 24) & 0x3f);
p[1] = 0x80 | ((wc >> 18) & 0x3f);
p[2] = 0x80 | ((wc >> 12) & 0x3f);
p[3] = 0x80 | ((wc >> 6) & 0x3f);
p[4] = 0x80 | (wc & 0x3f);
p += 6;
}
/* Ignore larger values; UTF-8 can't encode them. */
}
*p = '\0';
return (utf8_value);
}
static void
add_pax_attr_w(struct archive_string *as, const char *key, const wchar_t *wval)
{
char *utf8_value = utf8_encode(wval);
if (utf8_value == NULL)
return;
add_pax_attr(as, key, utf8_value);
free(utf8_value);
}
/*
* Add a key/value attribute to the pax header. This function handles
* the length field and various other syntactic requirements.
*/
static void
add_pax_attr(struct archive_string *as, const char *key, const char *value)
{
int digits, i, len, next_ten;
char tmp[1 + 3 * sizeof(int)]; /* < 3 base-10 digits per byte */
/*-
* PAX attributes have the following layout:
* <len> <space> <key> <=> <value> <nl>
*/
len = 1 + strlen(key) + 1 + strlen(value) + 1;
/*
* The <len> field includes the length of the <len> field, so
* computing the correct length is tricky. I start by
* counting the number of base-10 digits in 'len' and
* computing the next higher power of 10.
*/
next_ten = 1;
digits = 0;
i = len;
while (i > 0) {
i = i / 10;
digits++;
next_ten = next_ten * 10;
}
/*
* For example, if string without the length field is 99
* chars, then adding the 2 digit length "99" will force the
* total length past 100, requiring an extra digit. The next
* statement adjusts for this effect.
*/
if (len + digits >= next_ten)
digits++;
/* Now, we have the right length so we can build the line. */
tmp[sizeof(tmp) - 1] = 0; /* Null-terminate the work area. */
archive_strcat(as, format_int(tmp + sizeof(tmp) - 1, len + digits));
archive_strappend_char(as, ' ');
archive_strcat(as, key);
archive_strappend_char(as, '=');
archive_strcat(as, value);
archive_strappend_char(as, '\n');
}
static void
archive_write_pax_header_xattrs(struct pax *pax, struct archive_entry *entry)
{
struct archive_string s;
int i = archive_entry_xattr_reset(entry);
while (i--) {
const char *name;
const void *value;
char *encoded_value;
char *url_encoded_name = NULL, *encoded_name = NULL;
wchar_t *wcs_name = NULL;
size_t size;
archive_entry_xattr_next(entry, &name, &value, &size);
/* Name is URL-encoded, then converted to wchar_t,
* then UTF-8 encoded. */
url_encoded_name = url_encode(name);
if (url_encoded_name != NULL) {
/* Convert narrow-character to wide-character. */
int wcs_length = strlen(url_encoded_name);
wcs_name = malloc((wcs_length + 1) * sizeof(wchar_t));
if (wcs_name == NULL)
__archive_errx(1, "No memory for xattr conversion");
mbstowcs(wcs_name, url_encoded_name, wcs_length);
wcs_name[wcs_length] = 0;
free(url_encoded_name); /* Done with this. */
}
if (wcs_name != NULL) {
encoded_name = utf8_encode(wcs_name);
free(wcs_name); /* Done with wchar_t name. */
}
encoded_value = base64_encode(value, size);
if (encoded_name != NULL && encoded_value != NULL) {
archive_string_init(&s);
archive_strcpy(&s, "LIBARCHIVE.xattr.");
archive_strcat(&s, encoded_name);
add_pax_attr(&(pax->pax_header), s.s, encoded_value);
archive_string_free(&s);
}
free(encoded_name);
free(encoded_value);
}
}
/*
* TODO: Consider adding 'comment' and 'charset' fields to
* archive_entry so that clients can specify them. Also, consider
* adding generic key/value tags so clients can add arbitrary
* key/value data.
*/
static int
archive_write_pax_header(struct archive *a,
struct archive_entry *entry_original)
{
struct archive_entry *entry_main;
const char *linkname, *p;
const char *hardlink;
const wchar_t *wp;
const char *suffix_start;
int need_extension, r, ret;
struct pax *pax;
const struct stat *st_main, *st_original;
char paxbuff[512];
char ustarbuff[512];
char ustar_entry_name[256];
char pax_entry_name[256];
need_extension = 0;
pax = a->format_data;
pax->written = 1;
st_original = archive_entry_stat(entry_original);
hardlink = archive_entry_hardlink(entry_original);
/* Make sure this is a type of entry that we can handle here */
if (hardlink == NULL) {
switch (st_original->st_mode & S_IFMT) {
case S_IFREG:
case S_IFLNK:
case S_IFCHR:
case S_IFBLK:
case S_IFDIR:
case S_IFIFO:
break;
case S_IFSOCK:
archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
"tar format cannot archive socket");
return (ARCHIVE_WARN);
default:
archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
"tar format cannot archive this (mode=0%lo)",
(unsigned long)st_original->st_mode);
return (ARCHIVE_WARN);
}
}
/* Copy entry so we can modify it as needed. */
entry_main = archive_entry_clone(entry_original);
archive_string_empty(&(pax->pax_header)); /* Blank our work area. */
st_main = archive_entry_stat(entry_main);
/*
* Determining whether or not the name is too big is ugly
* because of the rules for dividing names between 'name' and
* 'prefix' fields. Here, I pick out the longest possible
* suffix, then test whether the remaining prefix is too long.
*/
wp = archive_entry_pathname_w(entry_main);
p = archive_entry_pathname(entry_main);
if (strlen(p) <= 100) /* Short enough for just 'name' field */
suffix_start = p; /* Record a zero-length prefix */
else
/* Find the largest suffix that fits in 'name' field. */
suffix_start = strchr(p + strlen(p) - 100 - 1, '/');
/*
* If name is too long, or has non-ASCII characters, add
* 'path' to pax extended attrs.
*/
if (suffix_start == NULL || suffix_start - p > 155 || has_non_ASCII(wp)) {
add_pax_attr_w(&(pax->pax_header), "path", wp);
archive_entry_set_pathname(entry_main,
build_ustar_entry_name(ustar_entry_name, p, strlen(p), NULL));
need_extension = 1;
}
/* If link name is too long or has non-ASCII characters, add
* 'linkpath' to pax extended attrs. */
linkname = hardlink;
if (linkname == NULL)
linkname = archive_entry_symlink(entry_main);
if (linkname != NULL) {
/* There is a link name, get the wide version as well. */
if (hardlink != NULL)
wp = archive_entry_hardlink_w(entry_main);
else
wp = archive_entry_symlink_w(entry_main);
/* If the link is long or has a non-ASCII character,
* store it as a pax extended attribute. */
if (strlen(linkname) > 100 || has_non_ASCII(wp)) {
add_pax_attr_w(&(pax->pax_header), "linkpath", wp);
if (hardlink != NULL)
archive_entry_set_hardlink(entry_main,
"././@LongHardLink");
else
archive_entry_set_symlink(entry_main,
"././@LongSymLink");
need_extension = 1;
}
}
/* If file size is too large, add 'size' to pax extended attrs. */
if (st_main->st_size >= (((int64_t)1) << 33)) {
add_pax_attr_int(&(pax->pax_header), "size", st_main->st_size);
need_extension = 1;
}
/* If numeric GID is too large, add 'gid' to pax extended attrs. */
if (st_main->st_gid >= (1 << 18)) {
add_pax_attr_int(&(pax->pax_header), "gid", st_main->st_gid);
need_extension = 1;
}
/* If group name is too large or has non-ASCII characters, add
* 'gname' to pax extended attrs. */
p = archive_entry_gname(entry_main);
wp = archive_entry_gname_w(entry_main);
if (p != NULL && (strlen(p) > 31 || has_non_ASCII(wp))) {
add_pax_attr_w(&(pax->pax_header), "gname", wp);
archive_entry_set_gname(entry_main, NULL);
need_extension = 1;
}
/* If numeric UID is too large, add 'uid' to pax extended attrs. */
if (st_main->st_uid >= (1 << 18)) {
add_pax_attr_int(&(pax->pax_header), "uid", st_main->st_uid);
need_extension = 1;
}
/* If user name is too large, add 'uname' to pax extended attrs. */
/* TODO: If uname has non-ASCII characters, use pax attribute. */
p = archive_entry_uname(entry_main);
wp = archive_entry_uname_w(entry_main);
if (p != NULL && (strlen(p) > 31 || has_non_ASCII(wp))) {
add_pax_attr_w(&(pax->pax_header), "uname", wp);
archive_entry_set_uname(entry_main, NULL);
need_extension = 1;
}
/*
* POSIX/SUSv3 doesn't provide a standard key for large device
* numbers. I use the same keys here that Joerg Schilling
* used for 'star.' (Which, somewhat confusingly, are called
* "devXXX" even though they code "rdev" values.) No doubt,
* other implementations use other keys. Note that there's no
* reason we can't write the same information into a number of
* different keys.
*
* Of course, this is only needed for block or char device entries.
*/
if (S_ISBLK(st_main->st_mode) ||
S_ISCHR(st_main->st_mode)) {
/*
* If rdevmajor is too large, add 'SCHILY.devmajor' to
* extended attributes.
*/
dev_t rdevmajor, rdevminor;
rdevmajor = major(st_main->st_rdev);
rdevminor = minor(st_main->st_rdev);
if (rdevmajor >= (1 << 18)) {
add_pax_attr_int(&(pax->pax_header), "SCHILY.devmajor",
rdevmajor);
/*
* Non-strict formatting below means we don't
* have to truncate here. Not truncating improves
* the chance that some more modern tar archivers
* (such as GNU tar 1.13) can restore the full
* value even if they don't understand the pax
* extended attributes. See my rant below about
* file size fields for additional details.
*/
/* archive_entry_set_rdevmajor(entry_main,
rdevmajor & ((1 << 18) - 1)); */
need_extension = 1;
}
/*
* If devminor is too large, add 'SCHILY.devminor' to
* extended attributes.
*/
if (rdevminor >= (1 << 18)) {
add_pax_attr_int(&(pax->pax_header), "SCHILY.devminor",
rdevminor);
/* Truncation is not necessary here, either. */
/* archive_entry_set_rdevminor(entry_main,
rdevminor & ((1 << 18) - 1)); */
need_extension = 1;
}
}
/*
* Technically, the mtime field in the ustar header can
* support 33 bits, but many platforms use signed 32-bit time
* values. The cutoff of 0x7fffffff here is a compromise.
* Yes, this check is duplicated just below; this helps to
* avoid writing an mtime attribute just to handle a
* high-resolution timestamp in "restricted pax" mode.
*/
if (!need_extension &&
((st_main->st_mtime < 0) || (st_main->st_mtime >= 0x7fffffff)))
need_extension = 1;
/* I use a star-compatible file flag attribute. */
p = archive_entry_fflags_text(entry_main);
if (!need_extension && p != NULL && *p != '\0')
need_extension = 1;
/* If there are non-trivial ACL entries, we need an extension. */
if (!need_extension && archive_entry_acl_count(entry_original,
ARCHIVE_ENTRY_ACL_TYPE_ACCESS) > 0)
need_extension = 1;
/* If there are non-trivial ACL entries, we need an extension. */
if (!need_extension && archive_entry_acl_count(entry_original,
ARCHIVE_ENTRY_ACL_TYPE_DEFAULT) > 0)
need_extension = 1;
/* If there are extended attributes, we need an extension */
if (!need_extension && archive_entry_xattr_count(entry_original) > 0)
need_extension = 1;
/*
* The following items are handled differently in "pax
* restricted" format. In particular, in "pax restricted"
* format they won't be added unless need_extension is
* already set (we're already generating an extended header, so
* may as well include these).
*/
if (a->archive_format != ARCHIVE_FORMAT_TAR_PAX_RESTRICTED ||
need_extension) {
if (st_main->st_mtime < 0 ||
st_main->st_mtime >= 0x7fffffff ||
ARCHIVE_STAT_MTIME_NANOS(st_main) != 0)
add_pax_attr_time(&(pax->pax_header), "mtime",
st_main->st_mtime,
ARCHIVE_STAT_MTIME_NANOS(st_main));
if (st_main->st_ctime != 0 ||
ARCHIVE_STAT_CTIME_NANOS(st_main) != 0)
add_pax_attr_time(&(pax->pax_header), "ctime",
st_main->st_ctime,
ARCHIVE_STAT_CTIME_NANOS(st_main));
if (st_main->st_atime != 0 ||
ARCHIVE_STAT_ATIME_NANOS(st_main) != 0)
add_pax_attr_time(&(pax->pax_header), "atime",
st_main->st_atime,
ARCHIVE_STAT_ATIME_NANOS(st_main));
/* I use a star-compatible file flag attribute. */
p = archive_entry_fflags_text(entry_main);
if (p != NULL && *p != '\0')
add_pax_attr(&(pax->pax_header), "SCHILY.fflags", p);
/* I use star-compatible ACL attributes. */
wp = archive_entry_acl_text_w(entry_original,
ARCHIVE_ENTRY_ACL_TYPE_ACCESS |
ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID);
if (wp != NULL && *wp != L'\0')
add_pax_attr_w(&(pax->pax_header),
"SCHILY.acl.access", wp);
wp = archive_entry_acl_text_w(entry_original,
ARCHIVE_ENTRY_ACL_TYPE_DEFAULT |
ARCHIVE_ENTRY_ACL_STYLE_EXTRA_ID);
if (wp != NULL && *wp != L'\0')
add_pax_attr_w(&(pax->pax_header),
"SCHILY.acl.default", wp);
/* Include star-compatible metadata info. */
/* Note: "SCHILY.dev{major,minor}" are NOT the
* major/minor portions of "SCHILY.dev". */
add_pax_attr_int(&(pax->pax_header), "SCHILY.dev",
st_main->st_dev);
add_pax_attr_int(&(pax->pax_header), "SCHILY.ino",
st_main->st_ino);
add_pax_attr_int(&(pax->pax_header), "SCHILY.nlink",
st_main->st_nlink);
/* Store extended attributes */
archive_write_pax_header_xattrs(pax, entry_original);
}
/* Only regular files have data. */
if (!S_ISREG(archive_entry_mode(entry_main)))
archive_entry_set_size(entry_main, 0);
/*
* Pax-restricted does not store data for hardlinks, in order
* to improve compatibility with ustar.
*/
if (a->archive_format != ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE &&
hardlink != NULL)
archive_entry_set_size(entry_main, 0);
/*
* XXX Full pax interchange format does permit a hardlink
* entry to have data associated with it. I'm not supporting
* that here because the client expects me to tell them whether
* or not this format expects data for hardlinks. If I
* don't check here, then every pax archive will end up with
* duplicated data for hardlinks. Someday, there may be
* need to select this behavior, in which case the following
* will need to be revisited. XXX
*/
if (hardlink != NULL)
archive_entry_set_size(entry_main, 0);
/* Format 'ustar' header for main entry.
*
* The trouble with file size: If the reader can't understand
* the file size, they may not be able to locate the next
* entry and the rest of the archive is toast. Pax-compliant
* readers are supposed to ignore the file size in the main
* header, so the question becomes how to maximize portability
* for readers that don't support pax attribute extensions.
* For maximum compatibility, I permit numeric extensions in
* the main header so that the file size stored will always be
* correct, even if it's in a format that only some
* implementations understand. The technique used here is:
*
* a) If possible, follow the standard exactly. This handles
* files up to 8 gigabytes minus 1.
*
* b) If that fails, try octal but omit the field terminator.
* That handles files up to 64 gigabytes minus 1.
*
* c) Otherwise, use base-256 extensions. That handles files
* up to 2^63 in this implementation, with the potential to
* go up to 2^94. That should hold us for a while. ;-)
*
* The non-strict formatter uses similar logic for other
* numeric fields, though they're less critical.
*/
__archive_write_format_header_ustar(a, ustarbuff, entry_main, -1, 0);
/* If we built any extended attributes, write that entry first. */
ret = ARCHIVE_OK;
if (archive_strlen(&(pax->pax_header)) > 0) {
struct stat st;
struct archive_entry *pax_attr_entry;
time_t s;
long ns;
memset(&st, 0, sizeof(st));
pax_attr_entry = archive_entry_new();
p = archive_entry_pathname(entry_main);
archive_entry_set_pathname(pax_attr_entry,
build_pax_attribute_name(pax_entry_name, p));
st.st_size = archive_strlen(&(pax->pax_header));
/* Copy uid/gid (but clip to ustar limits). */
st.st_uid = st_main->st_uid;
if (st.st_uid >= 1 << 18)
st.st_uid = (1 << 18) - 1;
st.st_gid = st_main->st_gid;
if (st.st_gid >= 1 << 18)
st.st_gid = (1 << 18) - 1;
/* Copy mode over (but not setuid/setgid bits) */
st.st_mode = st_main->st_mode;
#ifdef S_ISUID
st.st_mode &= ~S_ISUID;
#endif
#ifdef S_ISGID
st.st_mode &= ~S_ISGID;
#endif
#ifdef S_ISVTX
st.st_mode &= ~S_ISVTX;
#endif
archive_entry_copy_stat(pax_attr_entry, &st);
/* Copy uname/gname. */
archive_entry_set_uname(pax_attr_entry,
archive_entry_uname(entry_main));
archive_entry_set_gname(pax_attr_entry,
archive_entry_gname(entry_main));
/* Copy mtime, but clip to ustar limits. */
s = archive_entry_mtime(entry_main);
ns = archive_entry_mtime_nsec(entry_main);
if (s < 0) { s = 0; ns = 0; }
if (s > 0x7fffffff) { s = 0x7fffffff; ns = 0; }
archive_entry_set_mtime(pax_attr_entry, s, ns);
/* Ditto for atime. */
s = archive_entry_atime(entry_main);
ns = archive_entry_atime_nsec(entry_main);
if (s < 0) { s = 0; ns = 0; }
if (s > 0x7fffffff) { s = 0x7fffffff; ns = 0; }
archive_entry_set_atime(pax_attr_entry, s, ns);
/* Standard ustar doesn't support ctime. */
archive_entry_set_ctime(pax_attr_entry, 0, 0);
ret = __archive_write_format_header_ustar(a, paxbuff,
pax_attr_entry, 'x', 1);
archive_entry_free(pax_attr_entry);
/* Note that the 'x' header shouldn't ever fail to format */
if (ret != 0) {
const char *msg = "archive_write_pax_header: "
"'x' header failed?! This can't happen.\n";
write(2, msg, strlen(msg));
exit(1);
}
r = (a->compression_write)(a, paxbuff, 512);
if (r != ARCHIVE_OK) {
pax->entry_bytes_remaining = 0;
pax->entry_padding = 0;
return (ARCHIVE_FATAL);
}
pax->entry_bytes_remaining = archive_strlen(&(pax->pax_header));
pax->entry_padding = 0x1ff & (- pax->entry_bytes_remaining);
r = (a->compression_write)(a, pax->pax_header.s,
archive_strlen(&(pax->pax_header)));
if (r != ARCHIVE_OK) {
/* If a write fails, we're pretty much toast. */
return (ARCHIVE_FATAL);
}
/* Pad out the end of the entry. */
r = write_nulls(a, pax->entry_padding);
if (r != ARCHIVE_OK) {
/* If a write fails, we're pretty much toast. */
return (ARCHIVE_FATAL);
}
pax->entry_bytes_remaining = pax->entry_padding = 0;
}
/* Write the header for main entry. */
r = (a->compression_write)(a, ustarbuff, 512);
if (r != ARCHIVE_OK)
return (r);
/*
* Inform the client of the on-disk size we're using, so
* they can avoid unnecessarily writing a body for something
* that we're just going to ignore.
*/
archive_entry_set_size(entry_original, archive_entry_size(entry_main));
pax->entry_bytes_remaining = archive_entry_size(entry_main);
pax->entry_padding = 0x1ff & (- pax->entry_bytes_remaining);
archive_entry_free(entry_main);
return (ret);
}
/*
* We need a valid name for the regular 'ustar' entry. This routine
* tries to hack something more-or-less reasonable.
*
* The approach here tries to preserve leading dir names. We do so by
* working with four sections:
* 1) "prefix" directory names,
* 2) "suffix" directory names,
* 3) inserted dir name (optional),
* 4) filename.
*
* These sections must satisfy the following requirements:
* * Parts 1 & 2 together form an initial portion of the dir name.
* * Part 3 is specified by the caller. (It should not contain a leading
* or trailing '/'.)
* * Part 4 forms an initial portion of the base filename.
* * The filename must be <= 99 chars to fit the ustar 'name' field.
* * Parts 2, 3, 4 together must be <= 99 chars to fit the ustar 'name' fld.
* * Part 1 must be <= 155 chars to fit the ustar 'prefix' field.
* * If the original name ends in a '/', the new name must also end in a '/'
* * Trailing '/.' sequences may be stripped.
*
* Note: Recall that the ustar format does not store the '/' separating
* parts 1 & 2, but does store the '/' separating parts 2 & 3.
*/
static char *
build_ustar_entry_name(char *dest, const char *src, size_t src_length,
const char *insert)
{
const char *prefix, *prefix_end;
const char *suffix, *suffix_end;
const char *filename, *filename_end;
char *p;
int need_slash = 0; /* Was there a trailing slash? */
size_t suffix_length = 99;
int insert_length;
/* Length of additional dir element to be added. */
if (insert == NULL)
insert_length = 0;
else
/* +2 here allows for '/' before and after the insert. */
insert_length = strlen(insert) + 2;
/* Step 0: Quick bailout in a common case. */
if (src_length < 100 && insert == NULL) {
strncpy(dest, src, src_length);
dest[src_length] = '\0';
return (dest);
}
/* Step 1: Locate filename and enforce the length restriction. */
filename_end = src + src_length;
/* Remove trailing '/' chars and '/.' pairs. */
for (;;) {
if (filename_end > src && filename_end[-1] == '/') {
filename_end --;
need_slash = 1; /* Remember to restore trailing '/'. */
continue;
}
if (filename_end > src + 1 && filename_end[-1] == '.'
&& filename_end[-2] == '/') {
filename_end -= 2;
need_slash = 1; /* "foo/." will become "foo/" */
continue;
}
break;
}
if (need_slash)
suffix_length--;
/* Find start of filename. */
filename = filename_end - 1;
while ((filename > src) && (*filename != '/'))
filename --;
if ((*filename == '/') && (filename < filename_end - 1))
filename ++;
/* Adjust filename_end so that filename + insert fits in 99 chars. */
suffix_length -= insert_length;
if (filename_end > filename + suffix_length)
filename_end = filename + suffix_length;
/* Calculate max size for "suffix" section (#3 above). */
suffix_length -= filename_end - filename;
/* Step 2: Locate the "prefix" section of the dirname, including
* trailing '/'. */
prefix = src;
prefix_end = prefix + 155;
if (prefix_end > filename)
prefix_end = filename;
while (prefix_end > prefix && *prefix_end != '/')
prefix_end--;
if ((prefix_end < filename) && (*prefix_end == '/'))
prefix_end++;
/* Step 3: Locate the "suffix" section of the dirname,
* including trailing '/'. */
suffix = prefix_end;
suffix_end = suffix + suffix_length; /* Enforce limit. */
if (suffix_end > filename)
suffix_end = filename;
if (suffix_end < suffix)
suffix_end = suffix;
while (suffix_end > suffix && *suffix_end != '/')
suffix_end--;
if ((suffix_end < filename) && (*suffix_end == '/'))
suffix_end++;
/* Step 4: Build the new name. */
/* The OpenBSD strlcpy function is safer, but less portable. */
/* Rather than maintain two versions, just use the strncpy version. */
p = dest;
if (prefix_end > prefix) {
strncpy(p, prefix, prefix_end - prefix);
p += prefix_end - prefix;
}
if (suffix_end > suffix) {
strncpy(p, suffix, suffix_end - suffix);
p += suffix_end - suffix;
}
if (insert != NULL) {
/* Note: assume insert does not have leading or trailing '/' */
strcpy(p, insert);
p += strlen(insert);
*p++ = '/';
}
strncpy(p, filename, filename_end - filename);
p += filename_end - filename;
if (need_slash)
*p++ = '/';
*p++ = '\0';
return (dest);
}
/*
* The ustar header for the pax extended attributes must have a
* reasonable name: SUSv3 suggests 'dirname'/PaxHeader/'filename'
*
* Joerg Schiling has argued that this is unnecessary because, in practice,
* if the pax extended attributes get extracted as regular files, noone is
* going to bother reading those attributes to manually restore them.
* Based on this, 'star' uses /tmp/PaxHeader/'basename' as the ustar header
* name. This is a tempting argument, but I'm not entirely convinced.
* I'm also uncomfortable with the fact that "/tmp" is a Unix-ism.
*
* The following routine implements the SUSv3 recommendation, and is
* much simpler because build_ustar_entry_name() above already does
* most of the work (we just need to give it an extra path element to
* insert and handle a few pathological cases).
*/
static char *
build_pax_attribute_name(char *dest, const char *src)
{
const char *p;
/* Handle the null filename case. */
if (src == NULL || *src == '\0') {
strcpy(dest, "PaxHeader/blank");
return (dest);
}
/* Prune final '/' and other unwanted final elements. */
p = src + strlen(src);
for (;;) {
/* Ends in "/", remove the '/' */
if (p > src && p[-1] == '/') {
--p;
continue;
}
/* Ends in "/.", remove the '.' */
if (p > src + 1 && p[-1] == '.'
&& p[-2] == '/') {
--p;
continue;
}
break;
}
/* Pathological case: After above, there was nothing left.
* This includes "/." "/./." "/.//./." etc. */
if (p == src) {
strcpy(dest, "/PaxHeader/rootdir");
return (dest);
}
/* Convert unadorned "." into a suitable filename. */
if (*src == '.' && p == src + 1) {
strcpy(dest, "PaxHeader/currentdir");
return (dest);
}
/* General case: build a ustar-compatible name adding "/PaxHeader/". */
build_ustar_entry_name(dest, src, p - src, "PaxHeader");
return (dest);
}
/* Write two null blocks for the end of archive */
static int
archive_write_pax_finish(struct archive *a)
{
struct pax *pax;
int r;
r = ARCHIVE_OK;
pax = a->format_data;
if (pax->written && a->compression_write != NULL)
r = write_nulls(a, 512 * 2);
archive_string_free(&pax->pax_header);
free(pax);
a->format_data = NULL;
return (r);
}
static int
archive_write_pax_finish_entry(struct archive *a)
{
struct pax *pax;
int ret;
pax = a->format_data;
ret = write_nulls(a, pax->entry_bytes_remaining + pax->entry_padding);
pax->entry_bytes_remaining = pax->entry_padding = 0;
return (ret);
}
static int
write_nulls(struct archive *a, size_t padding)
{
int ret, to_write;
while (padding > 0) {
to_write = padding < a->null_length ? padding : a->null_length;
ret = (a->compression_write)(a, a->nulls, to_write);
if (ret != ARCHIVE_OK)
return (ret);
padding -= to_write;
}
return (ARCHIVE_OK);
}
static int
archive_write_pax_data(struct archive *a, const void *buff, size_t s)
{
struct pax *pax;
int ret;
pax = a->format_data;
pax->written = 1;
if (s > pax->entry_bytes_remaining)
s = pax->entry_bytes_remaining;
ret = (a->compression_write)(a, buff, s);
pax->entry_bytes_remaining -= s;
return (ret);
}
static int
has_non_ASCII(const wchar_t *wp)
{
while (*wp != L'\0' && *wp < 128)
wp++;
return (*wp != L'\0');
}
/*
* Used by extended attribute support; encodes the name
* so that there will be no '=' characters in the result.
*/
static char *
url_encode(const char *in)
{
const char *s;
char *d;
int out_len = 0;
char *out;
for (s = in; *s != '\0'; s++) {
if (*s < 33 || *s > 126 || *s == '%' || *s == '=')
out_len += 3;
else
out_len++;
}
out = (char *)malloc(out_len + 1);
if (out == NULL)
return (NULL);
for (s = in, d = out; *s != '\0'; s++) {
/* encode any non-printable ASCII character or '%' or '=' */
if (*s < 33 || *s > 126 || *s == '%' || *s == '=') {
/* URL encoding is '%' followed by two hex digits */
*d++ = '%';
*d++ = "0123456789ABCDEF"[0x0f & (*s >> 4)];
*d++ = "0123456789ABCDEF"[0x0f & *s];
} else {
*d++ = *s;
}
}
*d = '\0';
return (out);
}
/*
* Encode a sequence of bytes into a C string using base-64 encoding.
*
* Returns a null-terminated C string allocated with malloc(); caller
* is responsible for freeing the result.
*/
static char *
base64_encode(const char *s, size_t len)
{
static const char digits[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int v;
char *d, *out;
/* 3 bytes becomes 4 chars, but round up and allow for trailing NUL */
out = malloc((len * 4 + 2) / 3 + 1);
if (out == NULL)
return (NULL);
d = out;
/* Convert each group of 3 bytes into 4 characters. */
while (len >= 3) {
v = (((int)s[0] << 16) & 0xff0000)
| (((int)s[1] << 8) & 0xff00)
| (((int)s[2]) & 0x00ff);
s += 3;
len -= 3;
*d++ = digits[(v >> 18) & 0x3f];
*d++ = digits[(v >> 12) & 0x3f];
*d++ = digits[(v >> 6) & 0x3f];
*d++ = digits[(v) & 0x3f];
}
/* Handle final group of 1 byte (2 chars) or 2 bytes (3 chars). */
switch (len) {
case 0: break;
case 1:
v = (((int)s[0] << 16) & 0xff0000);
*d++ = digits[(v >> 18) & 0x3f];
*d++ = digits[(v >> 12) & 0x3f];
break;
case 2:
v = (((int)s[0] << 16) & 0xff0000)
| (((int)s[1] << 8) & 0xff00);
*d++ = digits[(v >> 18) & 0x3f];
*d++ = digits[(v >> 12) & 0x3f];
*d++ = digits[(v >> 6) & 0x3f];
break;
}
/* Add trailing NUL character so output is a valid C string. */
*d++ = '\0';
return (out);
}