Copy libarchive from vendor branch to contrib

MFC after:	2 weeks

1 files changed, 1386 insertions, 0 deletions

diff --git a/contrib/libarchive/libarchive/archive_write_set_format_pax.c b/contrib/libarchive/libarchive/archive_write_set_format_pax.c
new file mode 100644
index 0000000..00c3f3f
--- /dev/null
+++ b/contrib/libarchive/libarchive/archive_write_set_format_pax.c
@@ -0,0 +1,1386 @@
+/*-
+ * 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: head/lib/libarchive/archive_write_set_format_pax.c 201162 2009-12-29 05:47:46Z kientzle $");
+
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#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"
+
+struct pax {
+	uint64_t	entry_bytes_remaining;
+	uint64_t	entry_padding;
+	struct archive_string	pax_header;
+};
+
+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 ssize_t		 archive_write_pax_data(struct archive_write *,
+			     const void *, size_t);
+static int		 archive_write_pax_finish(struct archive_write *);
+static int		 archive_write_pax_destroy(struct archive_write *);
+static int		 archive_write_pax_finish_entry(struct archive_write *);
+static int		 archive_write_pax_header(struct archive_write *,
+			     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_write *, 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)
+{
+	struct archive_write *a = (struct archive_write *)_a;
+	int r;
+	r = archive_write_set_format_pax(&a->archive);
+	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_RESTRICTED;
+	a->archive.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 archive_write *a = (struct archive_write *)_a;
+	struct pax *pax;
+
+	if (a->format_destroy != NULL)
+		(a->format_destroy)(a);
+
+	pax = (struct pax *)malloc(sizeof(*pax));
+	if (pax == NULL) {
+		archive_set_error(&a->archive, ENOMEM, "Can't allocate pax data");
+		return (ARCHIVE_FATAL);
+	}
+	memset(pax, 0, sizeof(*pax));
+	a->format_data = pax;
+
+	a->pad_uncompressed = 1;
+	a->format_name = "pax";
+	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_destroy = archive_write_pax_destroy;
+	a->format_finish_entry = archive_write_pax_finish_entry;
+	a->archive.archive_format = ARCHIVE_FORMAT_TAR_PAX_INTERCHANGE;
+	a->archive.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 >= 0xd800 && wc <= 0xdbff
+		    && *wp >= 0xdc00 && *wp <= 0xdfff) {
+			/* This is a surrogate pair.  Combine into a
+			 * full Unicode value before encoding into
+			 * UTF-8. */
+			wc = (wc - 0xd800) << 10; /* High 10 bits */
+			wc += (*wp++ - 0xdc00); /* Low 10 bits */
+			wc += 0x10000; /* Skip BMP */
+		}
+		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 = (char *)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 >= 0xd800 && wc <= 0xdbff
+		    && *wp >= 0xdc00 && *wp <= 0xdfff) {
+			/* Combine surrogate pair. */
+			wc = (wc - 0xd800) << 10;
+			wc += *wp++ - 0xdc00 + 0x10000;
+		}
+		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 + (int)strlen(key) + 1 + (int)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. */
+			size_t wcs_length = strlen(url_encoded_name);
+			wcs_name = (wchar_t *)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((const char *)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_write *a,
+    struct archive_entry *entry_original)
+{
+	struct archive_entry *entry_main;
+	const char *p;
+	char *t;
+	const wchar_t *wp;
+	const char *suffix;
+	int need_extension, r, ret;
+	struct pax *pax;
+	const char *hdrcharset = NULL;
+	const char *hardlink;
+	const char *path = NULL, *linkpath = NULL;
+	const char *uname = NULL, *gname = NULL;
+	const wchar_t *path_w = NULL, *linkpath_w = NULL;
+	const wchar_t *uname_w = NULL, *gname_w = NULL;
+
+	char paxbuff[512];
+	char ustarbuff[512];
+	char ustar_entry_name[256];
+	char pax_entry_name[256];
+
+	ret = ARCHIVE_OK;
+	need_extension = 0;
+	pax = (struct pax *)a->format_data;
+
+	hardlink = archive_entry_hardlink(entry_original);
+
+	/* Make sure this is a type of entry that we can handle here */
+	if (hardlink == NULL) {
+		switch (archive_entry_filetype(entry_original)) {
+		case AE_IFBLK:
+		case AE_IFCHR:
+		case AE_IFIFO:
+		case AE_IFLNK:
+		case AE_IFREG:
+			break;
+		case AE_IFDIR:
+			/*
+			 * Ensure a trailing '/'.  Modify the original
+			 * entry so the client sees the change.
+			 */
+			p = archive_entry_pathname(entry_original);
+			if (p[strlen(p) - 1] != '/') {
+				t = (char *)malloc(strlen(p) + 2);
+				if (t == NULL) {
+					archive_set_error(&a->archive, ENOMEM,
+					"Can't allocate pax data");
+					return(ARCHIVE_FATAL);
+				}
+				strcpy(t, p);
+				strcat(t, "/");
+				archive_entry_copy_pathname(entry_original, t);
+				free(t);
+			}
+			break;
+		case AE_IFSOCK:
+			archive_set_error(&a->archive,
+			    ARCHIVE_ERRNO_FILE_FORMAT,
+			    "tar format cannot archive socket");
+			return (ARCHIVE_WARN);
+		default:
+			archive_set_error(&a->archive,
+			    ARCHIVE_ERRNO_FILE_FORMAT,
+			    "tar format cannot archive this (type=0%lo)",
+			    (unsigned long)archive_entry_filetype(entry_original));
+			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. */
+
+	/*
+	 * First, check the name fields and see if any of them
+	 * require binary coding.  If any of them does, then all of
+	 * them do.
+	 */
+	hdrcharset = NULL;
+	path = archive_entry_pathname(entry_main);
+	path_w = archive_entry_pathname_w(entry_main);
+	if (path != NULL && path_w == NULL) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+		    "Can't translate pathname '%s' to UTF-8", path);
+		ret = ARCHIVE_WARN;
+		hdrcharset = "BINARY";
+	}
+	uname = archive_entry_uname(entry_main);
+	uname_w = archive_entry_uname_w(entry_main);
+	if (uname != NULL && uname_w == NULL) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+		    "Can't translate uname '%s' to UTF-8", uname);
+		ret = ARCHIVE_WARN;
+		hdrcharset = "BINARY";
+	}
+	gname = archive_entry_gname(entry_main);
+	gname_w = archive_entry_gname_w(entry_main);
+	if (gname != NULL && gname_w == NULL) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+		    "Can't translate gname '%s' to UTF-8", gname);
+		ret = ARCHIVE_WARN;
+		hdrcharset = "BINARY";
+	}
+	linkpath = hardlink;
+	if (linkpath != NULL) {
+		linkpath_w = archive_entry_hardlink_w(entry_main);
+	} else {
+		linkpath = archive_entry_symlink(entry_main);
+		if (linkpath != NULL)
+			linkpath_w = archive_entry_symlink_w(entry_main);
+	}
+	if (linkpath != NULL && linkpath_w == NULL) {
+		archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+		    "Can't translate linkpath '%s' to UTF-8", linkpath);
+		ret = ARCHIVE_WARN;
+		hdrcharset = "BINARY";
+	}
+
+	/* Store the header encoding first, to be nice to readers. */
+	if (hdrcharset != NULL)
+		add_pax_attr(&(pax->pax_header), "hdrcharset", hdrcharset);
+
+
+	/*
+	 * If name is too long, or has non-ASCII characters, add
+	 * 'path' to pax extended attrs.  (Note that an unconvertible
+	 * name must have non-ASCII characters.)
+	 */
+	if (path == NULL) {
+		/* We don't have a narrow version, so we have to store
+		 * the wide version. */
+		add_pax_attr_w(&(pax->pax_header), "path", path_w);
+		archive_entry_set_pathname(entry_main, "@WidePath");
+		need_extension = 1;
+	} else if (has_non_ASCII(path_w)) {
+		/* We have non-ASCII characters. */
+		if (path_w == NULL || hdrcharset != NULL) {
+			/* Can't do UTF-8, so store it raw. */
+			add_pax_attr(&(pax->pax_header), "path", path);
+		} else {
+			/* Store UTF-8 */
+			add_pax_attr_w(&(pax->pax_header),
+			    "path", path_w);
+		}
+		archive_entry_set_pathname(entry_main,
+		    build_ustar_entry_name(ustar_entry_name,
+			path, strlen(path), NULL));
+		need_extension = 1;
+	} else {
+		/* We have an all-ASCII path; we'd like to just store
+		 * it in the ustar header if it will fit.  Yes, this
+		 * duplicates some of the logic in
+		 * write_set_format_ustar.c
+		 */
+		if (strlen(path) <= 100) {
+			/* Fits in the old 100-char tar name field. */
+		} else {
+			/* Find largest suffix that will fit. */
+			/* Note: strlen() > 100, so strlen() - 100 - 1 >= 0 */
+			suffix = strchr(path + strlen(path) - 100 - 1, '/');
+			/* Don't attempt an empty prefix. */
+			if (suffix == path)
+				suffix = strchr(suffix + 1, '/');
+			/* We can put it in the ustar header if it's
+			 * all ASCII and it's either <= 100 characters
+			 * or can be split at a '/' into a prefix <=
+			 * 155 chars and a suffix <= 100 chars.  (Note
+			 * the strchr() above will return NULL exactly
+			 * when the path can't be split.)
+			 */
+			if (suffix == NULL       /* Suffix > 100 chars. */
+			    || suffix[1] == '\0'    /* empty suffix */
+			    || suffix - path > 155)  /* Prefix > 155 chars */
+			{
+				if (path_w == NULL || hdrcharset != NULL) {
+					/* Can't do UTF-8, so store it raw. */
+					add_pax_attr(&(pax->pax_header),
+					    "path", path);
+				} else {
+					/* Store UTF-8 */
+					add_pax_attr_w(&(pax->pax_header),
+					    "path", path_w);
+				}
+				archive_entry_set_pathname(entry_main,
+				    build_ustar_entry_name(ustar_entry_name,
+					path, strlen(path), NULL));
+				need_extension = 1;
+			}
+		}
+	}
+
+	if (linkpath != NULL) {
+		/* If link name is too long or has non-ASCII characters, add
+		 * 'linkpath' to pax extended attrs. */
+		if (strlen(linkpath) > 100 || linkpath_w == NULL
+		    || linkpath_w == NULL || has_non_ASCII(linkpath_w)) {
+			if (linkpath_w == NULL || hdrcharset != NULL)
+				/* If the linkpath is not convertible
+				 * to wide, or we're encoding in
+				 * binary anyway, store it raw. */
+				add_pax_attr(&(pax->pax_header),
+				    "linkpath", linkpath);
+			else
+				/* If the link is long or has a
+				 * non-ASCII character, store it as a
+				 * pax extended attribute. */
+				add_pax_attr_w(&(pax->pax_header),
+				    "linkpath", linkpath_w);
+			if (strlen(linkpath) > 100) {
+				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 (archive_entry_size(entry_main) >= (((int64_t)1) << 33)) {
+		add_pax_attr_int(&(pax->pax_header), "size",
+		    archive_entry_size(entry_main));
+		need_extension = 1;
+	}
+
+	/* If numeric GID is too large, add 'gid' to pax extended attrs. */
+	if ((unsigned int)archive_entry_gid(entry_main) >= (1 << 18)) {
+		add_pax_attr_int(&(pax->pax_header), "gid",
+		    archive_entry_gid(entry_main));
+		need_extension = 1;
+	}
+
+	/* If group name is too large or has non-ASCII characters, add
+	 * 'gname' to pax extended attrs. */
+	if (gname != NULL) {
+		if (strlen(gname) > 31
+		    || gname_w == NULL
+		    || has_non_ASCII(gname_w))
+		{
+			if (gname_w == NULL || hdrcharset != NULL) {
+				add_pax_attr(&(pax->pax_header),
+				    "gname", gname);
+			} else  {
+				add_pax_attr_w(&(pax->pax_header),
+				    "gname", gname_w);
+			}
+			need_extension = 1;
+		}
+	}
+
+	/* If numeric UID is too large, add 'uid' to pax extended attrs. */
+	if ((unsigned int)archive_entry_uid(entry_main) >= (1 << 18)) {
+		add_pax_attr_int(&(pax->pax_header), "uid",
+		    archive_entry_uid(entry_main));
+		need_extension = 1;
+	}
+
+	/* Add 'uname' to pax extended attrs if necessary. */
+	if (uname != NULL) {
+		if (strlen(uname) > 31
+		    || uname_w == NULL
+		    || has_non_ASCII(uname_w))
+		{
+			if (uname_w == NULL || hdrcharset != NULL) {
+				add_pax_attr(&(pax->pax_header),
+				    "uname", uname);
+			} else {
+				add_pax_attr_w(&(pax->pax_header),
+				    "uname", uname_w);
+			}
+			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 (archive_entry_filetype(entry_main) == AE_IFBLK
+	    || archive_entry_filetype(entry_main) == AE_IFCHR) {
+		/*
+		 * If rdevmajor is too large, add 'SCHILY.devmajor' to
+		 * extended attributes.
+		 */
+		dev_t rdevmajor, rdevminor;
+		rdevmajor = archive_entry_rdevmajor(entry_main);
+		rdevminor = archive_entry_rdevminor(entry_main);
+		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 &&
+	    ((archive_entry_mtime(entry_main) < 0)
+		|| (archive_entry_mtime(entry_main) >= 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.archive_format != ARCHIVE_FORMAT_TAR_PAX_RESTRICTED ||
+	    need_extension) {
+
+		if (archive_entry_mtime(entry_main) < 0  ||
+		    archive_entry_mtime(entry_main) >= 0x7fffffff  ||
+		    archive_entry_mtime_nsec(entry_main) != 0)
+			add_pax_attr_time(&(pax->pax_header), "mtime",
+			    archive_entry_mtime(entry_main),
+			    archive_entry_mtime_nsec(entry_main));
+
+		if (archive_entry_ctime(entry_main) != 0  ||
+		    archive_entry_ctime_nsec(entry_main) != 0)
+			add_pax_attr_time(&(pax->pax_header), "ctime",
+			    archive_entry_ctime(entry_main),
+			    archive_entry_ctime_nsec(entry_main));
+
+		if (archive_entry_atime(entry_main) != 0 ||
+		    archive_entry_atime_nsec(entry_main) != 0)
+			add_pax_attr_time(&(pax->pax_header), "atime",
+			    archive_entry_atime(entry_main),
+			    archive_entry_atime_nsec(entry_main));
+
+		/* Store birth/creationtime only if it's earlier than mtime */
+		if (archive_entry_birthtime_is_set(entry_main) &&
+		    archive_entry_birthtime(entry_main)
+		    < archive_entry_mtime(entry_main))
+			add_pax_attr_time(&(pax->pax_header),
+			    "LIBARCHIVE.creationtime",
+			    archive_entry_birthtime(entry_main),
+			    archive_entry_birthtime_nsec(entry_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",
+		    archive_entry_dev(entry_main));
+		add_pax_attr_int(&(pax->pax_header), "SCHILY.ino",
+		    archive_entry_ino64(entry_main));
+		add_pax_attr_int(&(pax->pax_header), "SCHILY.nlink",
+		    archive_entry_nlink(entry_main));
+
+		/* Store extended attributes */
+		archive_write_pax_header_xattrs(pax, entry_original);
+	}
+
+	/* Only regular files have data. */
+	if (archive_entry_filetype(entry_main) != AE_IFREG)
+		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.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. */
+	if (archive_strlen(&(pax->pax_header)) > 0) {
+		struct archive_entry *pax_attr_entry;
+		time_t s;
+		uid_t uid;
+		gid_t gid;
+		mode_t mode;
+
+		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));
+		archive_entry_set_size(pax_attr_entry,
+		    archive_strlen(&(pax->pax_header)));
+		/* Copy uid/gid (but clip to ustar limits). */
+		uid = archive_entry_uid(entry_main);
+		if ((unsigned int)uid >= 1 << 18)
+			uid = (uid_t)(1 << 18) - 1;
+		archive_entry_set_uid(pax_attr_entry, uid);
+		gid = archive_entry_gid(entry_main);
+		if ((unsigned int)gid >= 1 << 18)
+			gid = (gid_t)(1 << 18) - 1;
+		archive_entry_set_gid(pax_attr_entry, gid);
+		/* Copy mode over (but not setuid/setgid bits) */
+		mode = archive_entry_mode(entry_main);
+#ifdef S_ISUID
+		mode &= ~S_ISUID;
+#endif
+#ifdef S_ISGID
+		mode &= ~S_ISGID;
+#endif
+#ifdef S_ISVTX
+		mode &= ~S_ISVTX;
+#endif
+		archive_entry_set_mode(pax_attr_entry, mode);
+
+		/* 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);
+		if (s < 0) { s = 0; }
+		if (s >= 0x7fffffff) { s = 0x7fffffff; }
+		archive_entry_set_mtime(pax_attr_entry, s, 0);
+
+		/* Standard ustar doesn't support atime. */
+		archive_entry_set_atime(pax_attr_entry, 0, 0);
+
+		/* Standard ustar doesn't support ctime. */
+		archive_entry_set_ctime(pax_attr_entry, 0, 0);
+
+		r = __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 (r != 0) {
+			const char *msg = "archive_write_pax_header: "
+			    "'x' header failed?!  This can't happen.\n";
+			size_t u = write(2, msg, strlen(msg));
+			(void)u; /* UNUSED */
+			exit(1);
+		}
+		r = (a->compressor.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 & (-(int64_t)pax->entry_bytes_remaining);
+
+		r = (a->compressor.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->compressor.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 & (-(int64_t)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;
+	size_t 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 requires 'dirname'/PaxHeader.'pid'/'filename'
+ * where 'pid' is the PID of the archiving process.  Unfortunately,
+ * that makes testing a pain since the output varies for each run,
+ * so I'm sticking with the simpler 'dirname'/PaxHeader/'filename'
+ * for now.  (Someday, I'll make this settable.  Then I can use the
+ * SUS recommendation as default and test harnesses can override it
+ * to get predictable results.)
+ *
+ * Joerg Schilling 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, in part because it's simpler than the SUSv3
+ * recommendation, but I'm not entirely convinced.  I'm also
+ * uncomfortable with the fact that "/tmp" is a Unix-ism.
+ *
+ * The following routine leverages build_ustar_entry_name() above and
+ * so is simpler than you might think.  It just needs to provide the
+ * additional path element and handle a few pathological cases).
+ */
+static char *
+build_pax_attribute_name(char *dest, const char *src)
+{
+	char buff[64];
+	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);
+	}
+
+	/*
+	 * TODO: Push this string into the 'pax' structure to avoid
+	 * recomputing it every time.  That will also open the door
+	 * to having clients override it.
+	 */
+#if HAVE_GETPID && 0  /* Disable this for now; see above comment. */
+	sprintf(buff, "PaxHeader.%d", getpid());
+#else
+	/* If the platform can't fetch the pid, don't include it. */
+	strcpy(buff, "PaxHeader");
+#endif
+	/* General case: build a ustar-compatible name adding "/PaxHeader/". */
+	build_ustar_entry_name(dest, src, p - src, buff);
+
+	return (dest);
+}
+
+/* Write two null blocks for the end of archive */
+static int
+archive_write_pax_finish(struct archive_write *a)
+{
+	int r;
+
+	if (a->compressor.write == NULL)
+		return (ARCHIVE_OK);
+
+	r = write_nulls(a, 512 * 2);
+	return (r);
+}
+
+static int
+archive_write_pax_destroy(struct archive_write *a)
+{
+	struct pax *pax;
+
+	pax = (struct pax *)a->format_data;
+	if (pax == NULL)
+		return (ARCHIVE_OK);
+
+	archive_string_free(&pax->pax_header);
+	free(pax);
+	a->format_data = NULL;
+	return (ARCHIVE_OK);
+}
+
+static int
+archive_write_pax_finish_entry(struct archive_write *a)
+{
+	struct pax *pax;
+	int ret;
+
+	pax = (struct 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_write *a, size_t padding)
+{
+	int ret;
+	size_t to_write;
+
+	while (padding > 0) {
+		to_write = padding < a->null_length ? padding : a->null_length;
+		ret = (a->compressor.write)(a, a->nulls, to_write);
+		if (ret != ARCHIVE_OK)
+			return (ret);
+		padding -= to_write;
+	}
+	return (ARCHIVE_OK);
+}
+
+static ssize_t
+archive_write_pax_data(struct archive_write *a, const void *buff, size_t s)
+{
+	struct pax *pax;
+	int ret;
+
+	pax = (struct pax *)a->format_data;
+	if (s > pax->entry_bytes_remaining)
+		s = pax->entry_bytes_remaining;
+
+	ret = (a->compressor.write)(a, buff, s);
+	pax->entry_bytes_remaining -= s;
+	if (ret == ARCHIVE_OK)
+		return (s);
+	else
+		return (ret);
+}
+
+static int
+has_non_ASCII(const wchar_t *wp)
+{
+	if (wp == NULL)
+		return (1);
+	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] =
+	    { 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O',
+	      'P','Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d',
+	      'e','f','g','h','i','j','k','l','m','n','o','p','q','r','s',
+	      't','u','v','w','x','y','z','0','1','2','3','4','5','6','7',
+	      '8','9','+','/' };
+	int v;
+	char *d, *out;
+
+	/* 3 bytes becomes 4 chars, but round up and allow for trailing NUL */
+	out = (char *)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);
+}