freebsd-dev/lib/libarchive/archive_write_set_format_cpio.c
Tim Kientzle 87a571f88a Essentially eliminate problems with false hardlinks in POSIX cpio
archives by generating synthetic ino values and mapping values
from disk into the new values.
2009-12-29 06:34:23 +00:00

345 lines
9.7 KiB
C

/*-
* Copyright (c) 2003-2007 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.
* 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("$FreeBSD$");
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "archive.h"
#include "archive_entry.h"
#include "archive_private.h"
#include "archive_write_private.h"
static ssize_t archive_write_cpio_data(struct archive_write *,
const void *buff, size_t s);
static int archive_write_cpio_finish(struct archive_write *);
static int archive_write_cpio_destroy(struct archive_write *);
static int archive_write_cpio_finish_entry(struct archive_write *);
static int archive_write_cpio_header(struct archive_write *,
struct archive_entry *);
static int format_octal(int64_t, void *, int);
static int64_t format_octal_recursive(int64_t, char *, int);
struct cpio {
uint64_t entry_bytes_remaining;
int64_t ino_next;
struct { int64_t old; int new;} *ino_list;
size_t ino_list_size;
size_t ino_list_next;
};
struct cpio_header {
char c_magic[6];
char c_dev[6];
char c_ino[6];
char c_mode[6];
char c_uid[6];
char c_gid[6];
char c_nlink[6];
char c_rdev[6];
char c_mtime[11];
char c_namesize[6];
char c_filesize[11];
};
/*
* Set output format to 'cpio' format.
*/
int
archive_write_set_format_cpio(struct archive *_a)
{
struct archive_write *a = (struct archive_write *)_a;
struct cpio *cpio;
/* If someone else was already registered, unregister them. */
if (a->format_destroy != NULL)
(a->format_destroy)(a);
cpio = (struct cpio *)malloc(sizeof(*cpio));
if (cpio == NULL) {
archive_set_error(&a->archive, ENOMEM, "Can't allocate cpio data");
return (ARCHIVE_FATAL);
}
memset(cpio, 0, sizeof(*cpio));
a->format_data = cpio;
a->pad_uncompressed = 1;
a->format_name = "cpio";
a->format_write_header = archive_write_cpio_header;
a->format_write_data = archive_write_cpio_data;
a->format_finish_entry = archive_write_cpio_finish_entry;
a->format_finish = archive_write_cpio_finish;
a->format_destroy = archive_write_cpio_destroy;
a->archive.archive_format = ARCHIVE_FORMAT_CPIO_POSIX;
a->archive.archive_format_name = "POSIX cpio";
return (ARCHIVE_OK);
}
/*
* Ino values are as long as 64 bits on some systems; cpio format
* only allows 18 bits and relies on the ino values to identify hardlinked
* files. So, we can't merely "hash" the ino numbers since collisions
* would corrupt the archive. Instead, we generate synthetic ino values
* to store in the archive and maintain a map of original ino values to
* synthetic ones so we can preserve hardlink information.
*
* TODO: Make this more efficient. It's not as bad as it looks (most
* files don't have any hardlinks and we don't do any work here for those),
* but it wouldn't be hard to do better.
*
* TODO: Work with dev/ino pairs here instead of just ino values.
*/
static int
synthesize_ino_value(struct cpio *cpio, struct archive_entry *entry)
{
int64_t ino = archive_entry_ino64(entry);
int ino_new;
size_t i;
/*
* If no index number was given, don't assign one. In
* particular, this handles the end-of-archive marker
* correctly by giving it a zero index value. (This is also
* why we start our synthetic index numbers with one below.)
*/
if (ino == 0)
return (0);
/* Don't store a mapping if we don't need to. */
if (archive_entry_nlink(entry) < 2) {
return ++cpio->ino_next;
}
/* Look up old ino; if we have it, this is a hardlink
* and we reuse the same value. */
for (i = 0; i < cpio->ino_list_next; ++i) {
if (cpio->ino_list[i].old == ino)
return (cpio->ino_list[i].new);
}
/* Assign a new index number. */
ino_new = ++cpio->ino_next;
/* Ensure space for the new mapping. */
if (cpio->ino_list_size <= cpio->ino_list_next) {
size_t newsize = cpio->ino_list_size < 512
? 512 : cpio->ino_list_size * 2;
void *newlist = realloc(cpio->ino_list,
sizeof(cpio->ino_list[0]) * newsize);
if (newlist == NULL)
return (-1);
cpio->ino_list_size = newsize;
cpio->ino_list = newlist;
}
/* Record and return the new value. */
cpio->ino_list[cpio->ino_list_next].old = ino;
cpio->ino_list[cpio->ino_list_next].new = ino_new;
++cpio->ino_list_next;
return (ino_new);
}
static int
archive_write_cpio_header(struct archive_write *a, struct archive_entry *entry)
{
struct cpio *cpio;
const char *p, *path;
int pathlength, ret, ret2;
int64_t ino;
struct cpio_header h;
cpio = (struct cpio *)a->format_data;
ret2 = ARCHIVE_OK;
path = archive_entry_pathname(entry);
pathlength = (int)strlen(path) + 1; /* Include trailing null. */
memset(&h, 0, sizeof(h));
format_octal(070707, &h.c_magic, sizeof(h.c_magic));
format_octal(archive_entry_dev(entry), &h.c_dev, sizeof(h.c_dev));
ino = synthesize_ino_value(cpio, entry);
if (ino < 0) {
archive_set_error(&a->archive, ENOMEM,
"No memory for ino translation table");
return (ARCHIVE_FATAL);
} else if (ino > 0777777) {
archive_set_error(&a->archive, ERANGE,
"Too many files for this cpio format");
return (ARCHIVE_FATAL);
}
format_octal(ino & 0777777, &h.c_ino, sizeof(h.c_ino));
format_octal(archive_entry_mode(entry), &h.c_mode, sizeof(h.c_mode));
format_octal(archive_entry_uid(entry), &h.c_uid, sizeof(h.c_uid));
format_octal(archive_entry_gid(entry), &h.c_gid, sizeof(h.c_gid));
format_octal(archive_entry_nlink(entry), &h.c_nlink, sizeof(h.c_nlink));
if (archive_entry_filetype(entry) == AE_IFBLK
|| archive_entry_filetype(entry) == AE_IFCHR)
format_octal(archive_entry_dev(entry), &h.c_rdev, sizeof(h.c_rdev));
else
format_octal(0, &h.c_rdev, sizeof(h.c_rdev));
format_octal(archive_entry_mtime(entry), &h.c_mtime, sizeof(h.c_mtime));
format_octal(pathlength, &h.c_namesize, sizeof(h.c_namesize));
/* Non-regular files don't store bodies. */
if (archive_entry_filetype(entry) != AE_IFREG)
archive_entry_set_size(entry, 0);
/* Symlinks get the link written as the body of the entry. */
p = archive_entry_symlink(entry);
if (p != NULL && *p != '\0')
format_octal(strlen(p), &h.c_filesize, sizeof(h.c_filesize));
else
format_octal(archive_entry_size(entry),
&h.c_filesize, sizeof(h.c_filesize));
ret = (a->compressor.write)(a, &h, sizeof(h));
if (ret != ARCHIVE_OK)
return (ARCHIVE_FATAL);
ret = (a->compressor.write)(a, path, pathlength);
if (ret != ARCHIVE_OK)
return (ARCHIVE_FATAL);
cpio->entry_bytes_remaining = archive_entry_size(entry);
/* Write the symlink now. */
if (p != NULL && *p != '\0')
ret = (a->compressor.write)(a, p, strlen(p));
if (ret == ARCHIVE_OK)
ret = ret2;
return (ret);
}
static ssize_t
archive_write_cpio_data(struct archive_write *a, const void *buff, size_t s)
{
struct cpio *cpio;
int ret;
cpio = (struct cpio *)a->format_data;
if (s > cpio->entry_bytes_remaining)
s = cpio->entry_bytes_remaining;
ret = (a->compressor.write)(a, buff, s);
cpio->entry_bytes_remaining -= s;
if (ret >= 0)
return (s);
else
return (ret);
}
/*
* Format a number into the specified field.
*/
static int
format_octal(int64_t v, void *p, int digits)
{
int64_t max;
int ret;
max = (((int64_t)1) << (digits * 3)) - 1;
if (v >= 0 && v <= max) {
format_octal_recursive(v, (char *)p, digits);
ret = 0;
} else {
format_octal_recursive(max, (char *)p, digits);
ret = -1;
}
return (ret);
}
static int64_t
format_octal_recursive(int64_t v, char *p, int s)
{
if (s == 0)
return (v);
v = format_octal_recursive(v, p+1, s-1);
*p = '0' + (v & 7);
return (v >> 3);
}
static int
archive_write_cpio_finish(struct archive_write *a)
{
int er;
struct archive_entry *trailer;
trailer = archive_entry_new();
/* nlink = 1 here for GNU cpio compat. */
archive_entry_set_nlink(trailer, 1);
archive_entry_set_pathname(trailer, "TRAILER!!!");
er = archive_write_cpio_header(a, trailer);
archive_entry_free(trailer);
return (er);
}
static int
archive_write_cpio_destroy(struct archive_write *a)
{
struct cpio *cpio;
cpio = (struct cpio *)a->format_data;
free(cpio->ino_list);
free(cpio);
a->format_data = NULL;
return (ARCHIVE_OK);
}
static int
archive_write_cpio_finish_entry(struct archive_write *a)
{
struct cpio *cpio;
size_t to_write;
int ret;
cpio = (struct cpio *)a->format_data;
ret = ARCHIVE_OK;
while (cpio->entry_bytes_remaining > 0) {
to_write = cpio->entry_bytes_remaining < a->null_length ?
cpio->entry_bytes_remaining : a->null_length;
ret = (a->compressor.write)(a, a->nulls, to_write);
if (ret != ARCHIVE_OK)
return (ret);
cpio->entry_bytes_remaining -= to_write;
}
return (ret);
}