cpio.c

早期freebsd实现

/*-
 * Copyright (c) 1992 Keith Muller.
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Keith Muller of the University of California, San Diego.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 */

#ifndef lint
static char sccsid[] = "@(#)cpio.c	8.1 (Berkeley) 5/31/93";
#endif /* not lint */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include "pax.h"
#include "cpio.h"
#include "extern.h"

static int rd_nm __P((register ARCHD *, int));
static int rd_ln_nm __P((register ARCHD *));
static int com_rd __P((register ARCHD *));

/*
 * Routines which support the different cpio versions
 */

static int swp_head;		/* binary cpio header byte swap */

/*
 * Routines common to all versions of cpio
 */

/*
 * cpio_strd()
 *	Fire up the hard link detection code
 * Return:
 *      0 if ok -1 otherwise (the return values of lnk_start())
 */

#if __STDC__
int
cpio_strd(void)
#else
int
cpio_strd()
#endif
{
	return(lnk_start());
}

/*
 * cpio_trail()
 *	Called to determine if a header block is a valid trailer. We are
 *	passed the block, the in_sync flag (which tells us we are in resync
 *	mode; looking for a valid header), and cnt (which starts at zero)
 *	which is used to count the number of empty blocks we have seen so far.
 * Return:
 *	0 if a valid trailer, -1 if not a valid trailer, 
 */

#if __STDC__
int
cpio_trail(register ARCHD *arcn)
#else
int
cpio_trail(arcn)
	register ARCHD *arcn;
#endif
{
	/*
	 * look for trailer id in file we are about to process
	 */
	if ((strcmp(arcn->name, TRAILER) == 0) && (arcn->sb.st_size == 0))
		return(0);
	return(-1);
}

/*
 * com_rd()
 *	operations common to all cpio read functions.
 * Return:
 *	0
 */

#if __STDC__
static int
com_rd(register ARCHD *arcn)
#else
static int
com_rd(arcn)
	register ARCHD *arcn;
#endif
{
	arcn->skip = 0;
	arcn->pat = NULL;
	arcn->org_name = arcn->name;
	switch(arcn->sb.st_mode & C_IFMT) {
	case C_ISFIFO:
		arcn->type = PAX_FIF;
		break;
	case C_ISDIR:
		arcn->type = PAX_DIR;
		break;
	case C_ISBLK:
		arcn->type = PAX_BLK;
		break;
	case C_ISCHR:
		arcn->type = PAX_CHR;
		break;
	case C_ISLNK:
		arcn->type = PAX_SLK;
		break;
	case C_ISOCK:
		arcn->type = PAX_SCK;
		break;
	case C_ISCTG:
	case C_ISREG:
	default:
		/*
		 * we have file data, set up skip (pad is set in the format
		 * specific sections)
		 */
		arcn->sb.st_mode = (arcn->sb.st_mode & 0xfff) | C_ISREG;
		arcn->type = PAX_REG;
		arcn->skip = arcn->sb.st_size;
		break;
	}
	if (chk_lnk(arcn) < 0)
		return(-1);
	return(0);
}

/*
 * cpio_end_wr()
 *	write the special file with the name trailer in the proper format
 * Return:
 *	result of the write of the trailer from the cpio specific write func
 */

#if __STDC__
int
cpio_endwr(void)
#else
int
cpio_endwr()
#endif
{
	ARCHD last;

	/*
	 * create a trailer request and call the proper format write function
	 */
	bzero((char *)&last, sizeof(last));
	last.nlen = sizeof(TRAILER) - 1;
	last.type = PAX_REG;
	last.sb.st_nlink = 1;
	(void)strcpy(last.name, TRAILER);
	return((*frmt->wr)(&last));
}

/*
 * rd_nam()
 *	read in the file name which follows the cpio header
 * Return:
 *	0 if ok, -1 otherwise
 */

#if __STDC__
static int
rd_nm(register ARCHD *arcn, int nsz)
#else
static int
rd_nm(arcn, nsz)
	register ARCHD *arcn;
	int nsz;
#endif
{
	/*
	 * do not even try bogus values
	 */
	if ((nsz == 0) || (nsz > sizeof(arcn->name))) {
		warn(1, "Cpio file name length %d is out of range", nsz);
		return(-1);
	}

	/*
	 * read the name and make sure it is not empty and is \0 terminated
	 */
	if ((rd_wrbuf(arcn->name,nsz) != nsz) || (arcn->name[nsz-1] != '\0') ||
	    (arcn->name[0] == '\0')) {
		warn(1, "Cpio file name in header is corrupted");
		return(-1);
	}
	return(0);
}

/*
 * rd_ln_nm()
 *	read in the link name for a file with links. The link name is stored
 *	like file data (and is NOT \0 terminated!)
 * Return:
 *	0 if ok, -1 otherwise
 */

#if __STDC__
static int
rd_ln_nm(register ARCHD *arcn)
#else
static int
rd_ln_nm(arcn)
	register ARCHD *arcn;
#endif
{
	/*
	 * check the length specified for bogus values
	 */
	if ((arcn->sb.st_size == 0) ||
	    (arcn->sb.st_size >= sizeof(arcn->ln_name))) {
#		ifdef NET2_STAT
		warn(1, "Cpio link name length is invalid: %lu",
		    arcn->sb.st_size);
#		else
		warn(1, "Cpio link name length is invalid: %qu",
		    arcn->sb.st_size);
#		endif
		return(-1);
	}

	/*
	 * read in the link name and \0 terminate it
	 */
	if (rd_wrbuf(arcn->ln_name, (int)arcn->sb.st_size) !=
	    (int)arcn->sb.st_size) {
		warn(1, "Cpio link name read error");
		return(-1);
	}
	arcn->ln_nlen = arcn->sb.st_size;
	arcn->ln_name[arcn->ln_nlen] = '\0';

	/*
	 * watch out for those empty link names
	 */
	if (arcn->ln_name[0] == '\0') {
		warn(1, "Cpio link name is corrupt");
		return(-1);
	}
	return(0);
}

/*
 * Routines common to the extended byte oriented cpio format
 */

/*
 * cpio_id()
 *      determine if a block given to us is a valid extended byte oriented
 *	cpio header
 * Return:
 *      0 if a valid header, -1 otherwise
 */

#if __STDC__
int
cpio_id(char *blk, int size)
#else
int
cpio_id(blk, size)
	char *blk;
	int size;
#endif
{
	if ((size < sizeof(HD_CPIO)) ||
	    (strncmp(blk, AMAGIC, sizeof(AMAGIC) - 1) != 0))
		return(-1);
	return(0);
}

/*
 * cpio_rd()
 *	determine if a buffer is a byte oriented extended cpio archive entry.
 *	convert and store the values in the ARCHD parameter.
 * Return:
 *	0 if a valid header, -1 otherwise.
 */

#if __STDC__
int
cpio_rd(register ARCHD *arcn, register char *buf)
#else
int
cpio_rd(arcn, buf)
	register ARCHD *arcn;
	register char *buf;
#endif
{
	register int nsz;
	register HD_CPIO *hd;

	/*
	 * check that this is a valid header, if not return -1
	 */
	if (cpio_id(buf, sizeof(HD_CPIO)) < 0)
		return(-1);
	hd = (HD_CPIO *)buf;

	/*
	 * byte oriented cpio (posix) does not have padding! extract the octal
	 * ascii fields from the header
	 */
	arcn->pad = 0L;
	arcn->sb.st_dev = (dev_t)asc_ul(hd->c_dev, sizeof(hd->c_dev), OCT);
	arcn->sb.st_ino = (ino_t)asc_ul(hd->c_ino, sizeof(hd->c_ino), OCT);
	arcn->sb.st_mode = (mode_t)asc_ul(hd->c_mode, sizeof(hd->c_mode), OCT);
	arcn->sb.st_uid = (uid_t)asc_ul(hd->c_uid, sizeof(hd->c_uid), OCT);
	arcn->sb.st_gid = (gid_t)asc_ul(hd->c_gid, sizeof(hd->c_gid), OCT);
	arcn->sb.st_nlink = (nlink_t)asc_ul(hd->c_nlink, sizeof(hd->c_nlink),
	    OCT);
	arcn->sb.st_rdev = (dev_t)asc_ul(hd->c_rdev, sizeof(hd->c_rdev), OCT);
	arcn->sb.st_mtime = (time_t)asc_ul(hd->c_mtime, sizeof(hd->c_mtime),
	    OCT);
	arcn->sb.st_ctime = arcn->sb.st_atime = arcn->sb.st_mtime;
#	ifdef NET2_STAT
	arcn->sb.st_size = (off_t)asc_ul(hd->c_filesize,sizeof(hd->c_filesize),
	    OCT);
#	else
	arcn->sb.st_size = (off_t)asc_uqd(hd->c_filesize,sizeof(hd->c_filesize),
	    OCT);
#	endif

	/*
	 * check name size and if valid, read in the name of this entry (name
	 * follows header in the archive)
	 */
	if ((nsz = (int)asc_ul(hd->c_namesize,sizeof(hd->c_namesize),OCT)) < 2)
		return(-1);
	arcn->nlen = nsz - 1;
	if (rd_nm(arcn, nsz) < 0)
		return(-1);

	if (((arcn->sb.st_mode&C_IFMT) != C_ISLNK)||(arcn->sb.st_size == 0)) {
		/*
	 	 * no link name to read for this file
	 	 */
		arcn->ln_nlen = 0;
		arcn->ln_name[0] = '\0';
		return(com_rd(arcn));
	}

	/*
	 * check link name size and read in the link name. Link names are
	 * stored like file data.
	 */
	if (rd_ln_nm(arcn) < 0)
		return(-1);

	/*
	 * we have a valid header (with a link)
	 */
	return(com_rd(arcn));
}

/*
 * cpio_endrd()
 *      no cleanup needed here, just return size of the trailer (for append)
 * Return:
 *      size of trailer header in this format
 */

#if __STDC__
off_t
cpio_endrd(void)
#else
off_t
cpio_endrd()
#endif
{
	return((off_t)(sizeof(HD_CPIO) + sizeof(TRAILER)));
}

/*
 * cpio_stwr()
 *	start up the device mapping table
 * Return:
 *	0 if ok, -1 otherwise (what dev_start() returns)
 */

#if __STDC__
int
cpio_stwr(void)
#else
int