initial import of NetBSD tree

1 files changed, 1198 insertions, 0 deletions

diff --git a/bin/pax/tar.c b/bin/pax/tar.c
new file mode 100644
index 00000000000..3c4597819e4
--- /dev/null
+++ b/bin/pax/tar.c
@@ -0,0 +1,1198 @@
+/*	$NetBSD: tar.c,v 1.5 1995/03/21 09:07:49 cgd Exp $	*/
+
+/*-
+ * 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
+#if 0
+static char sccsid[] = "@(#)tar.c	8.2 (Berkeley) 4/18/94";
+#else
+static char rcsid[] = "$NetBSD: tar.c,v 1.5 1995/03/21 09:07:49 cgd Exp $";
+#endif
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include "pax.h"
+#include "extern.h"
+#include "tar.h"
+
+/*
+ * Routines for reading, writing and header identify of various versions of tar
+ */
+
+static u_long tar_chksm __P((register char *, register int));
+static char *name_split __P((register char *, register int));
+static int ul_oct __P((u_long, register char *, register int, int));
+#ifndef NET2_STAT
+static int uqd_oct __P((u_quad_t, register char *, register int, int));
+#endif
+
+/*
+ * Routines common to all versions of tar
+ */
+
+static int tar_nodir;			/* do not write dirs under old tar */
+
+/*
+ * tar_endwr()
+ *	add the tar trailer of two null blocks
+ * Return:
+ *	0 if ok, -1 otherwise (what wr_skip returns)
+ */
+
+#if __STDC__
+int
+tar_endwr(void)
+#else
+int
+tar_endwr()
+#endif
+{
+	return(wr_skip((off_t)(NULLCNT*BLKMULT)));
+}
+
+/*
+ * tar_endrd()
+ *	no cleanup needed here, just return size of trailer (for append)
+ * Return:
+ *	size of trailer (2 * BLKMULT)
+ */
+
+#if __STDC__
+off_t
+tar_endrd(void)
+#else
+off_t
+tar_endrd()
+#endif
+{
+	return((off_t)(NULLCNT*BLKMULT));
+}
+
+/*
+ * tar_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, or 1 if the block
+ *	could never contain a header.
+ */
+
+#if __STDC__
+int
+tar_trail(register char *buf, register int in_resync, register int *cnt)
+#else
+int
+tar_trail(buf, in_resync, cnt)
+	register char *buf;
+	register int in_resync;
+	register int *cnt;
+#endif
+{
+	register int i;
+
+	/*
+	 * look for all zero, trailer is two consecutive blocks of zero
+	 */
+	for (i = 0; i < BLKMULT; ++i) {
+		if (buf[i] != '\0')
+			break;
+	}
+
+	/*
+	 * if not all zero it is not a trailer, but MIGHT be a header.
+	 */
+	if (i != BLKMULT)
+		return(-1);
+
+	/*
+	 * When given a zero block, we must be careful!
+	 * If we are not in resync mode, check for the trailer. Have to watch
+	 * out that we do not mis-identify file data as the trailer, so we do
+	 * NOT try to id a trailer during resync mode. During resync mode we
+	 * might as well throw this block out since a valid header can NEVER be
+	 * a block of all 0 (we must have a valid file name).
+	 */
+	if (!in_resync && (++*cnt >= NULLCNT))
+		return(0);
+	return(1);
+}
+
+/*
+ * ul_oct()
+ *	convert an unsigned long to an octal string. many oddball field
+ *	termination characters are used by the various versions of tar in the
+ *	different fields. term selects which kind to use. str is BLANK padded
+ *	at the front to len. we are unable to use only one format as many old
+ *	tar readers are very cranky about this.
+ * Return:
+ *	0 if the number fit into the string, -1 otherwise
+ */
+
+#if __STDC__
+static int
+ul_oct(u_long val, register char *str, register int len, int term)
+#else
+static int
+ul_oct(val, str, len, term)
+	u_long val;
+	register char *str;
+	register int len;
+	int term;
+#endif
+{
+	register char *pt;
+	
+	/*
+	 * term selects the appropriate character(s) for the end of the string
+	 */
+	pt = str + len - 1;
+	switch(term) {
+	case 3:
+		*pt-- = '\0';
+		break;
+	case 2:
+		*pt-- = ' ';
+		*pt-- = '\0';
+		break;
+	case 1:
+		*pt-- = ' ';
+		break;
+	case 0:
+	default:
+		*pt-- = '\0';
+		*pt-- = ' ';
+		break;
+	}
+
+	/*
+	 * convert and blank pad if there is space
+	 */
+	while (pt >= str) {
+		*pt-- = '0' + (char)(val & 0x7);
+		if ((val = val >> 3) == (u_long)0)
+			break;
+	}
+
+	while (pt >= str)
+		*pt-- = ' ';
+	if (val != (u_long)0)
+		return(-1);
+	return(0);
+}
+
+#ifndef NET2_STAT
+/*
+ * uqd_oct()
+ *	convert an u_quad_t to an octal string. one of many oddball field
+ *	termination characters are used by the various versions of tar in the
+ *	different fields. term selects which kind to use. str is BLANK padded
+ *	at the front to len. we are unable to use only one format as many old
+ *	tar readers are very cranky about this.
+ * Return:
+ *	0 if the number fit into the string, -1 otherwise
+ */
+
+#if __STDC__
+static int
+uqd_oct(u_quad_t val, register char *str, register int len, int term)
+#else
+static int
+uqd_oct(val, str, len, term)
+	u_quad_t val;
+	register char *str;
+	register int len;
+	int term;
+#endif
+{
+	register char *pt;
+	
+	/*
+	 * term selects the appropriate character(s) for the end of the string
+	 */
+	pt = str + len - 1;
+	switch(term) {
+	case 3:
+		*pt-- = '\0';
+		break;
+	case 2:
+		*pt-- = ' ';
+		*pt-- = '\0';
+		break;
+	case 1:
+		*pt-- = ' ';
+		break;
+	case 0:
+	default:
+		*pt-- = '\0';
+		*pt-- = ' ';
+		break;
+	}
+
+	/*
+	 * convert and blank pad if there is space
+	 */
+	while (pt >= str) {
+		*pt-- = '0' + (char)(val & 0x7);
+		if ((val = val >> 3) == 0)
+			break;
+	}
+
+	while (pt >= str)
+		*pt-- = ' ';
+	if (val != (u_quad_t)0)
+		return(-1);
+	return(0);
+}
+#endif
+
+/*
+ * tar_chksm()
+ *	calculate the checksum for a tar block counting the checksum field as
+ *	all blanks (BLNKSUM is that value pre-calculated, the sume of 8 blanks).
+ *	NOTE: we use len to short circuit summing 0's on write since we ALWAYS
+ *	pad headers with 0.
+ * Return:
+ *	unsigned long checksum
+ */
+
+#if __STDC__
+static u_long
+tar_chksm(register char *blk, register int len)
+#else
+static u_long
+tar_chksm(blk, len)
+	register char *blk;
+	register int len;
+#endif
+{
+	register char *stop;
+	register char *pt;
+	u_long chksm = BLNKSUM;	/* inital value is checksum field sum */
+
+	/*
+	 * add the part of the block before the checksum field
+	 */
+	pt = blk;
+	stop = blk + CHK_OFFSET;
+	while (pt < stop)	
+		chksm += (u_long)(*pt++ & 0xff);	
+	/*
+	 * move past the checksum field and keep going, spec counts the
+	 * checksum field as the sum of 8 blanks (which is pre-computed as
+	 * BLNKSUM).
+	 * ASSUMED: len is greater than CHK_OFFSET. (len is where our 0 padding
+	 * starts, no point in summing zero's)
+	 */
+	pt += CHK_LEN;
+	stop = blk + len;
+	while (pt < stop)
+		chksm += (u_long)(*pt++ & 0xff);	
+	return(chksm);
+}
+
+/*
+ * Routines for old BSD style tar (also made portable to sysV tar)
+ */
+
+/*
+ * tar_id()
+ *	determine if a block given to us is a valid tar header (and not a USTAR
+ *	header). We have to be on the lookout for those pesky blocks of	all
+ *	zero's.
+ * Return:
+ *	0 if a tar header, -1 otherwise
+ */
+
+#if __STDC__
+int
+tar_id(register char *blk, int size)
+#else
+int
+tar_id(blk, size)
+	register char *blk;
+	int size;
+#endif
+{
+	register HD_TAR *hd;
+	register HD_USTAR *uhd;
+
+	if (size < BLKMULT)
+		return(-1);
+	hd = (HD_TAR *)blk;
+	uhd = (HD_USTAR *)blk;
+
+	/*
+	 * check for block of zero's first, a simple and fast test, then make
+	 * sure this is not a ustar header by looking for the ustar magic
+	 * cookie. We should use TMAGLEN, but some USTAR archive programs are
+	 * wrong and create archives missing the \0. Last we check the
+	 * checksum. If this is ok we have to assume it is a valid header.
+	 */
+	if (hd->name[0] == '\0')
+		return(-1);
+	if (strncmp(uhd->magic, TMAGIC, TMAGLEN - 1) == 0)
+		return(-1);
+	if (asc_ul(hd->chksum,sizeof(hd->chksum),OCT) != tar_chksm(blk,BLKMULT))
+		return(-1);
+	return(0);
+}
+
+/*
+ * tar_opt()
+ *	handle tar format specific -o options
+ * Return:
+ *	0 if ok -1 otherwise
+ */
+
+#if __STDC__
+int
+tar_opt(void)
+#else
+int
+tar_opt()
+#endif
+{
+	OPLIST *opt;
+
+	while ((opt = opt_next()) != NULL) {
+		if (strcmp(opt->name, TAR_OPTION) ||
+		    strcmp(opt->value, TAR_NODIR)) {
+			warn(1, "Unknown tar format -o option/value pair %s=%s",
+			    opt->name, opt->value);
+			warn(1,"%s=%s is the only supported tar format option",
+			    TAR_OPTION, TAR_NODIR);
+			return(-1);
+		}
+
+		/*
+		 * we only support one option, and only when writing
+		 */
+		if ((act != APPND) && (act != ARCHIVE)) {
+			warn(1, "%s=%s is only supported when writing.",
+			    opt->name, opt->value);
+			return(-1);
+		}
+		tar_nodir = 1;
+	}
+	return(0);
+}
+
+
+/*
+ * tar_rd()
+ *	extract the values out of block already determined to be a tar header.
+ *	store the values in the ARCHD parameter.
+ * Return:
+ *	0
+ */
+
+#if __STDC__
+int
+tar_rd(register ARCHD *arcn, register char *buf)
+#else
+int
+tar_rd(arcn, buf)
+	register ARCHD *arcn;
+	register char *buf;
+#endif
+{
+	register HD_TAR *hd;
+	register char *pt;
+
+	/*
+	 * we only get proper sized buffers passed to us
+	 */
+	if (tar_id(buf, BLKMULT) < 0)
+		return(-1);
+	arcn->org_name = arcn->name;
+	arcn->sb.st_nlink = 1;
+	arcn->pat = NULL;
+
+	/*
+	 * copy out the name and values in the stat buffer
+	 */
+	hd = (HD_TAR *)buf;
+	arcn->nlen = l_strncpy(arcn->name, hd->name, sizeof(hd->name));
+	arcn->name[arcn->nlen] = '\0';
+	arcn->sb.st_mode = (mode_t)(asc_ul(hd->mode,sizeof(hd->mode),OCT) &
+	    0xfff);
+	arcn->sb.st_uid = (uid_t)asc_ul(hd->uid, sizeof(hd->uid), OCT);
+	arcn->sb.st_gid = (gid_t)asc_ul(hd->gid, sizeof(hd->gid), OCT);
+	arcn->sb.st_size = (size_t)asc_ul(hd->size, sizeof(hd->size), OCT);
+	arcn->sb.st_mtime = (time_t)asc_ul(hd->mtime, sizeof(hd->mtime), OCT);
+	arcn->sb.st_ctime = arcn->sb.st_atime = arcn->sb.st_mtime;
+
+	/*
+	 * have to look at the last character, it may be a '/' and that is used
+	 * to encode this as a directory
+	 */
+	pt = &(arcn->name[arcn->nlen - 1]);
+	arcn->pad = 0;
+	arcn->skip = 0;
+	switch(hd->linkflag) {
+	case SYMTYPE:
+		/*
+		 * symbolic link, need to get the link name and set the type in
+		 * the st_mode so -v printing will look correct.
+		 */
+		arcn->type = PAX_SLK;
+		arcn->ln_nlen = l_strncpy(arcn->ln_name, hd->linkname,
+			sizeof(hd->linkname));
+		arcn->ln_name[arcn->ln_nlen] = '\0';
+		arcn->sb.st_mode |= S_IFLNK;
+		break;
+	case LNKTYPE:
+		/*
+		 * hard link, need to get the link name, set the type in the
+		 * st_mode and st_nlink so -v printing will look better.
+		 */
+		arcn->type = PAX_HLK;
+		arcn->sb.st_nlink = 2;
+		arcn->ln_nlen = l_strncpy(arcn->ln_name, hd->linkname,
+			sizeof(hd->linkname));
+		arcn->ln_name[arcn->ln_nlen] = '\0';
+
+		/*
+		 * no idea of what type this thing really points at, but
+		 * we set something for printing only.
+		 */
+		arcn->sb.st_mode |= S_IFREG;
+		break;
+	case AREGTYPE:
+	case REGTYPE:
+	default:
+		/*
+		 * If we have a trailing / this is a directory and NOT a file.
+		 */
+		arcn->ln_name[0] = '\0';
+		arcn->ln_nlen = 0;
+		if (*pt == '/') {
+			/*
+			 * it is a directory, set the mode for -v printing
+			 */
+			arcn->type = PAX_DIR;
+			arcn->sb.st_mode |= S_IFDIR;
+			arcn->sb.st_nlink = 2;
+		} else {
+			/*
+			 * have a file that will be followed by data. Set the
+			 * skip value to the size field and caluculate the size
+			 * of the padding.
+			 */
+			arcn->type = PAX_REG;
+			arcn->sb.st_mode |= S_IFREG;
+			arcn->pad = TAR_PAD(arcn->sb.st_size);
+			arcn->skip = arcn->sb.st_size;
+		}
+		break;
+	}
+
+	/*
+	 * strip off any trailing slash.
+	 */
+	if (*pt == '/') {
+		*pt = '\0'; 
+		--arcn->nlen;
+	}
+	return(0);
+}
+
+/*
+ * tar_wr()
+ *	write a tar header for the file specified in the ARCHD to the archive.
+ *	Have to check for file types that cannot be stored and file names that
+ *	are too long. Be careful of the term (last arg) to ul_oct, each field
+ *	of tar has it own spec for the termination character(s).
+ *	ASSUMED: space after header in header block is zero filled
+ * Return:
+ *	0 if file has data to be written after the header, 1 if file has NO
+ *	data to write after the header, -1 if archive write failed
+ */
+
+#if __STDC__
+int
+tar_wr(register ARCHD *arcn)
+#else
+int
+tar_wr(arcn)
+	register ARCHD *arcn;
+#endif
+{
+	register HD_TAR *hd;
+	int len;
+	char hdblk[sizeof(HD_TAR)];
+
+	/*
+	 * check for those file system types which tar cannot store
+	 */
+	switch(arcn->type) {
+	case PAX_DIR:
+		/*
+		 * user asked that dirs not be written to the archive
+		 */
+		if (tar_nodir)
+			return(1);
+		break;
+	case PAX_CHR:
+		warn(1, "Tar cannot archive a character device %s",
+		    arcn->org_name);
+		return(1);
+	case PAX_BLK:
+		warn(1, "Tar cannot archive a block device %s", arcn->org_name);
+		return(1);
+	case PAX_SCK:
+		warn(1, "Tar cannot archive a socket %s", arcn->org_name);
+		return(1);
+	case PAX_FIF:
+		warn(1, "Tar cannot archive a fifo %s", arcn->org_name);
+		return(1);
+	case PAX_SLK:
+	case PAX_HLK:
+	case PAX_HRG:
+		if (arcn->ln_nlen > sizeof(hd->linkname)) {
+			warn(1,"Link name too long for tar %s", arcn->ln_name);
+			return(1);
+		}
+		break;
+	case PAX_REG:
+	case PAX_CTG:
+	default:
+		break;
+	}
+
+	/*
+	 * check file name len, remember extra char for dirs (the / at the end)
+	 */
+	len = arcn->nlen;
+	if (arcn->type == PAX_DIR)
+		++len;
+	if (len > sizeof(hd->name)) {
+		warn(1, "File name too long for tar %s", arcn->name);
+		return(1);
+	}
+
+	/*
+	 * copy the data out of the ARCHD into the tar header based on the type
+	 * of the file. Remember many tar readers want the unused fields to be
+	 * padded with zero. We set the linkflag field (type), the linkname
+	 * (or zero if not used),the size, and set the padding (if any) to be
+	 * added after the file data (0 for all other types, as they only have
+	 * a header)
+	 */
+	hd = (HD_TAR *)hdblk;
+	zf_strncpy(hd->name, arcn->name, sizeof(hd->name));
+	arcn->pad = 0;
+
+	if (arcn->type == PAX_DIR) {
+		/*
+		 * directories are the same as files, except have a filename
+		 * that ends with a /, we add the slash here. No data follows,
+		 * dirs, so no pad.
+		 */
+		hd->linkflag = AREGTYPE;
+		memset(hd->linkname, 0, sizeof(hd->linkname));
+		hd->name[len-1] = '/';
+		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 1))
+			goto out;
+	} else if (arcn->type == PAX_SLK) {
+		/*
+		 * no data follows this file, so no pad
+		 */
+		hd->linkflag = SYMTYPE;
+		zf_strncpy(hd->linkname,arcn->ln_name, sizeof(hd->linkname));
+		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 1))
+			goto out;
+	} else if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG)) {
+		/*
+		 * no data follows this file, so no pad
+		 */
+		hd->linkflag = LNKTYPE;
+		zf_strncpy(hd->linkname,arcn->ln_name, sizeof(hd->linkname));
+		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 1))
+			goto out;
+	} else {
+		/*
+		 * data follows this file, so set the pad
+		 */
+		hd->linkflag = AREGTYPE;
+		memset(hd->linkname, 0, sizeof(hd->linkname));
+#		ifdef NET2_STAT
+		if (ul_oct((u_long)arcn->sb.st_size, hd->size,
+		    sizeof(hd->size), 1)) {
+#		else
+		if (uqd_oct((u_quad_t)arcn->sb.st_size, hd->size,
+		    sizeof(hd->size), 1)) {
+#		endif
+			warn(1,"File is too large for tar %s", arcn->org_name);
+			return(1);
+		}
+		arcn->pad = TAR_PAD(arcn->sb.st_size);
+	}
+
+	/*
+	 * copy those fields that are independent of the type
+	 */
+	if (ul_oct((u_long)arcn->sb.st_mode, hd->mode, sizeof(hd->mode), 0) ||
+	    ul_oct((u_long)arcn->sb.st_uid, hd->uid, sizeof(hd->uid), 0) ||
+	    ul_oct((u_long)arcn->sb.st_gid, hd->gid, sizeof(hd->gid), 0) ||
+	    ul_oct((u_long)arcn->sb.st_mtime, hd->mtime, sizeof(hd->mtime), 1))
+		goto out;
+
+	/*
+	 * calculate and add the checksum, then write the header. A return of
+	 * 0 tells the caller to now write the file data, 1 says no data needs
+	 * to be written
+	 */
+	if (ul_oct(tar_chksm(hdblk, sizeof(HD_TAR)), hd->chksum,
+	    sizeof(hd->chksum), 2))
+		goto out;
+	if (wr_rdbuf(hdblk, sizeof(HD_TAR)) < 0)
+		return(-1);
+	if (wr_skip((off_t)(BLKMULT - sizeof(HD_TAR))) < 0)
+		return(-1);
+	if ((arcn->type == PAX_CTG) || (arcn->type == PAX_REG))
+		return(0);
+	return(1);
+
+    out:
+	/*
+	 * header field is out of range
+	 */
+	warn(1, "Tar header field is too small for %s", arcn->org_name);
+	return(1);
+}
+
+/*
+ * Routines for POSIX ustar
+ */
+
+/*
+ * ustar_strd()
+ *	initialization for ustar read
+ * Return:
+ *	0 if ok, -1 otherwise
+ */
+
+#if __STDC__
+int
+ustar_strd(void)
+#else
+int
+ustar_strd()
+#endif
+{
+	if ((usrtb_start() < 0) || (grptb_start() < 0))
+		return(-1);
+	return(0);
+}
+
+/*
+ * ustar_stwr()
+ *	initialization for ustar write
+ * Return:
+ *	0 if ok, -1 otherwise
+ */
+
+#if __STDC__
+int
+ustar_stwr(void)
+#else
+int
+ustar_stwr()
+#endif
+{
+	if ((uidtb_start() < 0) || (gidtb_start() < 0))
+		return(-1);
+	return(0);
+}
+
+/*
+ * ustar_id()
+ *	determine if a block given to us is a valid ustar header. We have to
+ *	be on the lookout for those pesky blocks of all zero's
+ * Return:
+ *	0 if a ustar header, -1 otherwise
+ */
+
+#if __STDC__
+int
+ustar_id(char *blk, int size)
+#else
+int
+ustar_id(blk, size)
+	char *blk;
+	int size;
+#endif
+{
+	register HD_USTAR *hd;
+
+	if (size < BLKMULT)
+		return(-1);
+	hd = (HD_USTAR *)blk;
+
+	/*
+	 * check for block of zero's first, a simple and fast test then check
+	 * ustar magic cookie. We should use TMAGLEN, but some USTAR archive
+	 * programs are fouled up and create archives missing the \0. Last we
+	 * check the checksum. If ok we have to assume it is a valid header.
+	 */
+	if (hd->name[0] == '\0')
+		return(-1);
+	if (strncmp(hd->magic, TMAGIC, TMAGLEN - 1) != 0)
+		return(-1);
+	if (asc_ul(hd->chksum,sizeof(hd->chksum),OCT) != tar_chksm(blk,BLKMULT))
+		return(-1);
+	return(0);
+}
+
+/*
+ * ustar_rd()
+ *	extract the values out of block already determined to be a ustar header.
+ *	store the values in the ARCHD parameter.
+ * Return:
+ *	0
+ */
+
+#if __STDC__
+int
+ustar_rd(register ARCHD *arcn, register char *buf)
+#else
+int
+ustar_rd(arcn, buf)
+	register ARCHD *arcn;
+	register char *buf;
+#endif
+{
+	register HD_USTAR *hd;
+	register char *dest;
+	register int cnt = 0;
+	dev_t devmajor;
+	dev_t devminor;
+
+	/*
+	 * we only get proper sized buffers
+	 */
+	if (ustar_id(buf, BLKMULT) < 0)
+		return(-1);
+	arcn->org_name = arcn->name;
+	arcn->sb.st_nlink = 1;
+	arcn->pat = NULL;
+	hd = (HD_USTAR *)buf;
+
+	/*
+	 * see if the filename is split into two parts. if, so joint the parts.
+	 * we copy the prefix first and add a / between the prefix and name.
+	 */
+	dest = arcn->name;
+	if (*(hd->prefix) != '\0') {
+		cnt = l_strncpy(arcn->name, hd->prefix, sizeof(hd->prefix));
+		dest = arcn->name + arcn->nlen;
+		*dest++ = '/';
+	}
+	arcn->nlen = l_strncpy(dest, hd->name, sizeof(hd->name));
+	arcn->nlen += cnt;
+	arcn->name[arcn->nlen] = '\0';
+
+	/*
+	 * follow the spec to the letter. we should only have mode bits, strip
+	 * off all other crud we may be passed.
+	 */
+	arcn->sb.st_mode = (mode_t)(asc_ul(hd->mode, sizeof(hd->mode), OCT) &
+	    0xfff);
+	arcn->sb.st_size = (size_t)asc_ul(hd->size, sizeof(hd->size), OCT);
+	arcn->sb.st_mtime = (time_t)asc_ul(hd->mtime, sizeof(hd->mtime), OCT);
+	arcn->sb.st_ctime = arcn->sb.st_atime = arcn->sb.st_mtime;
+
+	/*
+	 * If we can find the ascii names for gname and uname in the password
+	 * and group files we will use the uid's and gid they bind. Otherwise
+	 * we use the uid and gid values stored in the header. (This is what
+	 * the posix spec wants).
+	 */
+	hd->gname[sizeof(hd->gname) - 1] = '\0';
+	if (gid_name(hd->gname, &(arcn->sb.st_gid)) < 0)
+		arcn->sb.st_gid = (gid_t)asc_ul(hd->gid, sizeof(hd->gid), OCT);
+	hd->uname[sizeof(hd->uname) - 1] = '\0';
+	if (uid_name(hd->uname, &(arcn->sb.st_uid)) < 0)
+		arcn->sb.st_uid = (uid_t)asc_ul(hd->uid, sizeof(hd->uid), OCT);
+
+	/*
+	 * set the defaults, these may be changed depending on the file type
+	 */
+	arcn->ln_name[0] = '\0';
+	arcn->ln_nlen = 0;
+	arcn->pad = 0;
+	arcn->skip = 0;
+	arcn->sb.st_rdev = (dev_t)0;
+
+	/*
+	 * set the mode and PAX type according to the typeflag in the header
+	 */
+	switch(hd->typeflag) {
+	case FIFOTYPE:
+		arcn->type = PAX_FIF;
+		arcn->sb.st_mode |= S_IFIFO;
+		break;
+	case DIRTYPE:
+		arcn->type = PAX_DIR;
+		arcn->sb.st_mode |= S_IFDIR;
+		arcn->sb.st_nlink = 2;
+
+		/*
+		 * Some programs that create ustar archives append a '/'
+		 * to the pathname for directories. This clearly violates
+		 * ustar specs, but we will silently strip it off anyway.
+		 */
+		if (arcn->name[arcn->nlen - 1] == '/')
+			arcn->name[--arcn->nlen] = '\0';
+		break;
+	case BLKTYPE:
+	case CHRTYPE:
+		/*
+		 * this type requires the rdev field to be set.
+		 */
+		if (hd->typeflag == BLKTYPE) {
+			arcn->type = PAX_BLK;
+			arcn->sb.st_mode |= S_IFBLK;
+		} else {
+			arcn->type = PAX_CHR;
+			arcn->sb.st_mode |= S_IFCHR;
+		}
+		devmajor = (dev_t)asc_ul(hd->devmajor,sizeof(hd->devmajor),OCT);
+		devminor = (dev_t)asc_ul(hd->devminor,sizeof(hd->devminor),OCT);
+		arcn->sb.st_rdev = TODEV(devmajor, devminor);
+		break;
+	case SYMTYPE:
+	case LNKTYPE:
+		if (hd->typeflag == SYMTYPE) {
+			arcn->type = PAX_SLK;
+			arcn->sb.st_mode |= S_IFLNK;
+		} else {
+			arcn->type = PAX_HLK;
+			/*
+			 * so printing looks better
+			 */
+			arcn->sb.st_mode |= S_IFREG;
+			arcn->sb.st_nlink = 2;
+		}
+		/*
+		 * copy the link name
+		 */
+		arcn->ln_nlen = l_strncpy(arcn->ln_name, hd->linkname,
+			sizeof(hd->linkname));
+		arcn->ln_name[arcn->ln_nlen] = '\0';
+		break;
+	case CONTTYPE:
+	case AREGTYPE:
+	case REGTYPE:
+	default:
+		/*
+		 * these types have file data that follows. Set the skip and
+		 * pad fields.
+		 */
+		arcn->type = PAX_REG;
+		arcn->pad = TAR_PAD(arcn->sb.st_size);
+		arcn->skip = arcn->sb.st_size;
+		arcn->sb.st_mode |= S_IFREG;
+		break;
+	}
+	return(0);
+}
+
+/*
+ * ustar_wr()
+ *	write a ustar header for the file specified in the ARCHD to the archive
+ *	Have to check for file types that cannot be stored and file names that
+ *	are too long. Be careful of the term (last arg) to ul_oct, we only use
+ *	'\0' for the termination character (this is different than picky tar)
+ *	ASSUMED: space after header in header block is zero filled
+ * Return:
+ *	0 if file has data to be written after the header, 1 if file has NO
+ *	data to write after the header, -1 if archive write failed
+ */
+
+#if __STDC__
+int
+ustar_wr(register ARCHD *arcn)
+#else
+int
+ustar_wr(arcn)
+	register ARCHD *arcn;
+#endif
+{
+	register HD_USTAR *hd;
+	register char *pt;
+	char hdblk[sizeof(HD_USTAR)];
+
+	/*
+	 * check for those file system types ustar cannot store
+	 */
+	if (arcn->type == PAX_SCK) {
+		warn(1, "Ustar cannot archive a socket %s", arcn->org_name);
+		return(1);
+	}
+
+	/*
+	 * check the length of the linkname
+	 */
+	if (((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) ||
+	    (arcn->type == PAX_HRG)) && (arcn->ln_nlen > sizeof(hd->linkname))){
+		warn(1, "Link name too long for ustar %s", arcn->ln_name);
+		return(1);
+	}
+
+	/*
+	 * split the path name into prefix and name fields (if needed). if
+	 * pt != arcn->name, the name has to be split
+	 */
+	if ((pt = name_split(arcn->name, arcn->nlen)) == NULL) {
+		warn(1, "File name too long for ustar %s", arcn->name);
+		return(1);
+	}
+	hd = (HD_USTAR *)hdblk;
+	arcn->pad = 0L;
+
+	/*
+	 * split the name, or zero out the prefix
+	 */
+	if (pt != arcn->name) {
+		/*
+		 * name was split, pt points at the / where the split is to
+		 * occur, we remove the / and copy the first part to the prefix
+		 */
+		*pt = '\0';
+		zf_strncpy(hd->prefix, arcn->name, sizeof(hd->prefix));
+		*pt++ = '/';
+	} else
+		memset(hd->prefix, 0, sizeof(hd->prefix));
+
+	/*
+	 * copy the name part. this may be the whole path or the part after
+	 * the prefix
+	 */
+	zf_strncpy(hd->name, pt, sizeof(hd->name));
+
+	/* 
+	 * set the fields in the header that are type dependent
+	 */
+	switch(arcn->type) {
+	case PAX_DIR:
+		hd->typeflag = DIRTYPE;
+		memset(hd->linkname, 0, sizeof(hd->linkname));
+		memset(hd->devmajor, 0, sizeof(hd->devmajor));
+		memset(hd->devminor, 0, sizeof(hd->devminor));
+		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 3))
+			goto out;
+		break;
+	case PAX_CHR:
+	case PAX_BLK:
+		if (arcn->type == PAX_CHR)
+			hd->typeflag = CHRTYPE;
+		else
+			hd->typeflag = BLKTYPE;
+		memset(hd->linkname, 0, sizeof(hd->linkname));
+		if (ul_oct((u_long)MAJOR(arcn->sb.st_rdev), hd->devmajor,
+		   sizeof(hd->devmajor), 3) ||
+		   ul_oct((u_long)MINOR(arcn->sb.st_rdev), hd->devminor,
+		   sizeof(hd->devminor), 3) ||
+		   ul_oct((u_long)0L, hd->size, sizeof(hd->size), 3))
+			goto out;
+		break;
+	case PAX_FIF:
+		hd->typeflag = FIFOTYPE;
+		memset(hd->linkname, 0, sizeof(hd->linkname));
+		memset(hd->devmajor, 0, sizeof(hd->devmajor));
+		memset(hd->devminor, 0, sizeof(hd->devminor));
+		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 3))
+			goto out;
+		break;
+	case PAX_SLK:
+	case PAX_HLK:
+	case PAX_HRG:
+		if (arcn->type == PAX_SLK)
+			hd->typeflag = SYMTYPE;
+		else
+			hd->typeflag = LNKTYPE;
+		zf_strncpy(hd->linkname,arcn->ln_name, sizeof(hd->linkname));
+		memset(hd->devmajor, 0, sizeof(hd->devmajor));
+		memset(hd->devminor, 0, sizeof(hd->devminor));
+		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 3))
+			goto out;
+		break;
+	case PAX_REG:
+	case PAX_CTG:
+	default:
+		/*
+		 * file data with this type, set the padding
+		 */
+		if (arcn->type == PAX_CTG)
+			hd->typeflag = CONTTYPE;
+		else
+			hd->typeflag = REGTYPE;
+		memset(hd->linkname, 0, sizeof(hd->linkname));
+		memset(hd->devmajor, 0, sizeof(hd->devmajor));
+		memset(hd->devminor, 0, sizeof(hd->devminor));
+		arcn->pad = TAR_PAD(arcn->sb.st_size);
+#		ifdef NET2_STAT
+		if (ul_oct((u_long)arcn->sb.st_size, hd->size,
+		    sizeof(hd->size), 3)) {
+#		else
+		if (uqd_oct((u_quad_t)arcn->sb.st_size, hd->size,
+		    sizeof(hd->size), 3)) {
+#		endif
+			warn(1,"File is too long for ustar %s",arcn->org_name);
+			return(1);
+		}
+		break;
+	}
+
+	zf_strncpy(hd->magic, TMAGIC, TMAGLEN);
+	zf_strncpy(hd->version, TVERSION, TVERSLEN);
+
+	/*
+	 * set the remaining fields. Some versions want all 16 bits of mode
+	 * we better humor them (they really do not meet spec though)....
+	 */
+	if (ul_oct((u_long)arcn->sb.st_mode, hd->mode, sizeof(hd->mode), 3) ||
+	    ul_oct((u_long)arcn->sb.st_uid, hd->uid, sizeof(hd->uid), 3)  ||
+	    ul_oct((u_long)arcn->sb.st_gid, hd->gid, sizeof(hd->gid), 3) ||
+	    ul_oct((u_long)arcn->sb.st_mtime,hd->mtime,sizeof(hd->mtime),3))
+		goto out;
+	zf_strncpy(hd->uname,name_uid(arcn->sb.st_uid, 0),sizeof(hd->uname));
+	zf_strncpy(hd->gname,name_gid(arcn->sb.st_gid, 0),sizeof(hd->gname));
+
+	/*
+	 * calculate and store the checksum write the header to the archive
+	 * return 0 tells the caller to now write the file data, 1 says no data
+	 * needs to be written
+	 */
+	if (ul_oct(tar_chksm(hdblk, sizeof(HD_USTAR)), hd->chksum,
+	   sizeof(hd->chksum), 3))
+		goto out;
+	if (wr_rdbuf(hdblk, sizeof(HD_USTAR)) < 0)
+		return(-1);
+	if (wr_skip((off_t)(BLKMULT - sizeof(HD_USTAR))) < 0)
+		return(-1);
+	if ((arcn->type == PAX_CTG) || (arcn->type == PAX_REG))
+		return(0);
+	return(1);
+
+    out:
+    	/*
+	 * header field is out of range
+	 */
+	warn(1, "Ustar header field is too small for %s", arcn->org_name);
+	return(1);
+}
+
+/*
+ * name_split()
+ *	see if the name has to be split for storage in a ustar header. We try
+ *	to fit the entire name in the name field without splitting if we can.
+ *	The split point is always at a /
+ * Return
+ *	character pointer to split point (always the / that is to be removed
+ *	if the split is not needed, the points is set to the start of the file
+ *	name (it would violate the spec to split there). A NULL is returned if
+ *	the file name is too long
+ */
+
+#if __STDC__
+static char *
+name_split(register char *name, register int len)
+#else
+static char *
+name_split(name, len)
+	register char *name;
+	register int len;
+#endif
+{
+	register char *start;
+
+	/*
+	 * check to see if the file name is small enough to fit in the name
+	 * field. if so just return a pointer to the name.
+	 */
+	if (len <= TNMSZ)
+		return(name);
+	if (len > (TPFSZ + TNMSZ + 1))
+		return(NULL);
+
+	/*
+	 * we start looking at the biggest sized piece that fits in the name
+	 * field. We walk foward looking for a slash to split at. The idea is
+	 * to find the biggest piece to fit in the name field (or the smallest
+	 * prefix we can find) (the -1 is correct the biggest piece would
+	 * include the slash between the two parts that gets thrown away)
+	 */
+	start = name + len - TNMSZ - 1;
+	while ((*start != '\0') && (*start != '/'))
+		++start;
+
+	/*
+	 * if we hit the end of the string, this name cannot be split, so we
+	 * cannot store this file.
+	 */
+	if (*start == '\0')
+		return(NULL);
+	len = start - name;
+
+	/*
+	 * NOTE: /str where the length of str == TNMSZ can not be stored under
+	 * the p1003.1-1990 spec for ustar. We could force a prefix of / and
+	 * the file would then expand on extract to //str. The len == 0 below
+	 * makes this special case follow the spec to the letter.
+	 */
+	if ((len > TPFSZ) || (len == 0))
+		return(NULL);
+
+	/*
+	 * ok have a split point, return it to the caller
+	 */
+	return(start);
+}