freebsd-nq/lib/libarchive/archive_write_set_format_pax.c
Tim Kientzle d6970563b6 Fix two ugly errors:
1. The correct cutoff for large uid/gid handling is 1<<18, not 1<<20.
2. Limit the uid/gid in the 'x' extension header (where numeric extensions
are not permitted) to 1<<18, but use the correct value in the regular
header (where numeric extensions are permitted).
Thanks to: Dan Nelson
MFC after: 3 days
2004-09-17 04:39:07 +00:00

864 lines
26 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>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wchar.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 *build_pax_attribute_name(const char *abbreviated,
struct archive_string *work);
static char *build_ustar_entry_name(char *dest, const char *src);
static char *format_int(char *dest, int64_t);
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 void
add_pax_attr_w(struct archive_string *as, const char *key, 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);
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';
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');
}
/*
* 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, *wp2, *wname_start;
int need_extension, oldstate, r, ret;
struct pax *pax;
const struct stat *st_main, *st_original;
struct archive_string pax_entry_name;
char paxbuff[512];
char ustarbuff[512];
char ustar_entry_name[256];
archive_string_init(&pax_entry_name);
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 (wcslen(wp) <= 100) /* Short enough for just 'name' field */
wname_start = wp; /* Record a zero-length prefix */
else
/* Find the largest suffix that fits in 'name' field. */
wname_start = wcschr(wp + wcslen(wp) - 100 - 1, '/');
/* Find non-ASCII character, if any. */
wp2 = wp;
while (*wp2 != L'\0' && *wp2 < 128)
wp2++;
/*
* If name is too long, or has non-ASCII characters, add
* 'path' to pax extended attrs.
*/
if (wname_start == NULL || wname_start - wp > 155 ||
*wp2 != L'\0') {
add_pax_attr_w(&(pax->pax_header), "path", wp);
archive_entry_set_pathname(entry_main,
build_ustar_entry_name(ustar_entry_name, p));
need_extension = 1;
}
/* If link name is too long, add 'linkpath' to pax extended attrs. */
linkname = hardlink;
if (linkname == NULL)
linkname = archive_entry_symlink(entry_main);
if (linkname != NULL && strlen(linkname) > 100) {
add_pax_attr(&(pax->pax_header), "linkpath", linkname);
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, add 'gname' to pax extended attrs. */
/* TODO: If gname has non-ASCII characters, use pax attribute. */
p = archive_entry_gname(entry_main);
if (p != NULL && strlen(p) > 31) {
add_pax_attr(&(pax->pax_header), "gname", p);
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);
if (p != NULL && strlen(p) > 31) {
add_pax_attr(&(pax->pax_header), "uname", p);
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);
archive_entry_set_rdevmajor(entry_main, (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);
archive_entry_set_rdevminor(entry_main, (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;
/*
* 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 generated 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);
}
/* 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 = 0;
if (archive_strlen(&(pax->pax_header)) > 0) {
struct stat st;
struct archive_entry *pax_attr_entry;
const char *pax_attr_name;
memset(&st, 0, sizeof(st));
pax_attr_entry = archive_entry_new();
p = archive_entry_pathname(entry_main);
pax_attr_name = build_pax_attribute_name(p, &pax_entry_name);
archive_entry_set_pathname(pax_attr_entry, pax_attr_name);
st.st_size = archive_strlen(&(pax->pax_header));
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;
st.st_mode = st_main->st_mode;
archive_entry_copy_stat(pax_attr_entry, &st);
archive_entry_set_uname(pax_attr_entry,
archive_entry_uname(entry_main));
archive_entry_set_gname(pax_attr_entry,
archive_entry_gname(entry_main));
ret = __archive_write_format_header_ustar(a, paxbuff,
pax_attr_entry, 'x', 1);
archive_entry_free(pax_attr_entry);
archive_string_free(&pax_entry_name);
/* Note that the 'x' header shouldn't ever fail to format */
if (ret != 0) {
const char *msg = "archive_write_header_pax: "
"'x' header failed?! This can't happen.\n";
write(2, msg, strlen(msg));
exit(1);
}
r = (a->compression_write)(a, paxbuff, 512);
if (r < 512) {
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);
oldstate = a->state;
a->state = ARCHIVE_STATE_DATA;
r = archive_write_data(a, pax->pax_header.s,
archive_strlen(&(pax->pax_header)));
a->state = oldstate;
if (r < (int)archive_strlen(&(pax->pax_header))) {
/* If a write fails, we're pretty much toast. */
return (ARCHIVE_FATAL);
}
archive_write_pax_finish_entry(a);
}
/* Write the header for main entry. */
r = (a->compression_write)(a, ustarbuff, 512);
if (ret != ARCHIVE_OK)
ret = (r < 512) ? ARCHIVE_FATAL : ARCHIVE_OK;
/*
* 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.
*/
static char *
build_ustar_entry_name(char *dest, const char *src)
{
const char *basename, *break_point, *prefix;
int basename_length, dirname_length, prefix_length;
prefix = src;
basename = strrchr(src, '/');
if (basename == NULL) {
basename = src;
prefix_length = 0;
basename_length = strlen(basename);
if (basename_length > 100)
basename_length = 100;
} else {
basename_length = strlen(basename);
if (basename_length > 100)
basename_length = 100;
dirname_length = basename - src;
break_point =
strchr(src + dirname_length + basename_length - 101, '/');
prefix_length = break_point - prefix - 1;
while (prefix_length > 155) {
prefix = strchr(prefix, '/') + 1; /* Drop 1st dir. */
prefix_length = break_point - prefix - 1;
}
}
/* The OpenBSD strlcpy function is safer, but less portable. */
/* Rather than maintain two versions, just use the strncpy version. */
strncpy(dest, prefix, basename - prefix + basename_length);
dest[basename - prefix + basename_length] = '\0';
return (dest);
}
/*
* The ustar header for the pax extended attributes must have a
* reasonable name: SUSv3 suggests 'dirname'/PaxHeaders/'basename'
*
* 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.
* This is a tempting argument, but I'm not entirely convinced.
*
* Of course, adding "PaxHeaders/" might force the name to be too big.
* Here, I start from the (possibly already-trimmed) name used in the
* main ustar header and delete some additional early path elements to
* fit in the extra "PaxHeader/" part.
*/
static char *
build_pax_attribute_name(const char *abbreviated, /* ustar-compat name */
struct archive_string *work)
{
const char *basename, *break_point, *prefix;
int prefix_length, suffix_length;
/*
* This is much simpler because I know that "abbreviated" is
* already small enough; I just need to determine if it needs
* any further trimming to fit the "PaxHeader/" portion.
*/
/* Identify the final prefix and suffix portions. */
prefix = abbreviated; /* First guess: prefix starts at beginning */
if (strlen(abbreviated) > 100) {
break_point = strchr(prefix + strlen(prefix) - 101, '/');
prefix_length = break_point - prefix - 1;
suffix_length = strlen(break_point + 1);
/*
* The next loop keeps trimming until "/PaxHeader/" can
* be added to either the prefix or the suffix.
*/
while (prefix_length > 144 && suffix_length > 89) {
prefix = strchr(prefix, '/') + 1; /* Drop 1st dir. */
prefix_length = break_point - prefix - 1;
}
}
archive_string_empty(work);
basename = strrchr(prefix, '/');
if (basename == NULL) {
archive_strcpy(work, "PaxHeader/");
archive_strcat(work, prefix);
} else {
basename++;
archive_strncpy(work, prefix, basename - prefix);
archive_strcat(work, "PaxHeader/");
archive_strcat(work, basename);
}
return (work->s);
}
/* 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 <= 0)
return (ARCHIVE_FATAL);
padding -= ret;
}
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);
}