Add support for using mtree(5) manifest files to define the image

to be created. The support is based on mtree version 2.0, as used
in libarchive, but adds new features on top of it.

The current implementation is fully functional, but is envisioned
to grow at least the following additional features over time:
o   Add support for the /include special command so that manifest
    files can be constructed using includable fragments.
o   Add support specifying a search path to locate content files.
o   Content file filters: commands that provide file contents on
    stdout.

The manifest file eliminates the need to first construct a tree
as root in order to create an image and allows images (releases)
to be created directly from object trees and/or source trees.

Reviewed by:	deo
Sponsored by:	Juniper Networks, Inc

7 files changed, 1111 insertions, 18 deletions

diff --git a/usr.sbin/makefs/Makefile b/usr.sbin/makefs/Makefile
index 37eeb38..6fa0679 100644
--- a/usr.sbin/makefs/Makefile
+++ b/usr.sbin/makefs/Makefile
@@ -7,6 +7,7 @@ CFLAGS+=-I${.CURDIR}
 SRCS=	cd9660.c ffs.c \
 	getid.c \
 	makefs.c \
+	mtree.c \
 	walk.c
 MAN=	makefs.8
 
@@ -26,4 +27,7 @@ SRCS+=	misc.c spec.c
 .PATH:	${.CURDIR}/../../sys/ufs/ffs
 SRCS+=	ffs_tables.c
 
+DPADD=  ${LIBSBUF}
+LDADD=  -lsbuf
+
 .include <bsd.prog.mk>
diff --git a/usr.sbin/makefs/cd9660/cd9660_write.c b/usr.sbin/makefs/cd9660/cd9660_write.c
index 46d4a34..4622701 100644
--- a/usr.sbin/makefs/cd9660/cd9660_write.c
+++ b/usr.sbin/makefs/cd9660/cd9660_write.c
@@ -294,10 +294,12 @@ cd9660_write_file(FILE *fd, cd9660node *writenode)
 			INODE_WARNX(("%s: writing inode %d blocks at %" PRIu32,
 			    __func__, (int)inode->st.st_ino, inode->ino));
 			inode->flags |= FI_WRITTEN;
-			cd9660_compute_full_filename(writenode,
-			    temp_file_name, 0);
+			if (writenode->node->contents == NULL)
+				cd9660_compute_full_filename(writenode,
+				    temp_file_name, 0);
 			ret = cd9660_copy_file(fd, writenode->fileDataSector,
-			    temp_file_name);
+			    (writenode->node->contents != NULL) ?
+			    writenode->node->contents : temp_file_name);
 			if (ret == 0)
 				goto out;
 		}
diff --git a/usr.sbin/makefs/ffs.c b/usr.sbin/makefs/ffs.c
index a3c9d68..f833cf5 100644
--- a/usr.sbin/makefs/ffs.c
+++ b/usr.sbin/makefs/ffs.c
@@ -776,9 +776,11 @@ ffs_populate_dir(const char *dir, fsnode *root, fsinfo_t *fsopts)
 			continue;		/* skip hard-linked entries */
 		cur->inode->flags |= FI_WRITTEN;
 
-		if (snprintf(path, sizeof(path), "%s/%s", dir, cur->name)
-		    >= sizeof(path))
-			errx(1, "Pathname too long.");
+		if (cur->contents == NULL) {
+			if (snprintf(path, sizeof(path), "%s/%s", dir,
+			    cur->name) >= sizeof(path))
+				errx(1, "Pathname too long.");
+		}
 
 		if (cur->child != NULL)
 			continue;		/* child creates own inode */
@@ -802,7 +804,8 @@ ffs_populate_dir(const char *dir, fsnode *root, fsinfo_t *fsopts)
 		if (membuf != NULL) {
 			ffs_write_file(&din, cur->inode->ino, membuf, fsopts);
 		} else if (S_ISREG(cur->type)) {
-			ffs_write_file(&din, cur->inode->ino, path, fsopts);
+			ffs_write_file(&din, cur->inode->ino,
+			    (cur->contents) ?  cur->contents : path, fsopts);
 		} else {
 			assert (! S_ISDIR(cur->type));
 			ffs_write_inode(&din, cur->inode->ino, fsopts);
diff --git a/usr.sbin/makefs/makefs.8 b/usr.sbin/makefs/makefs.8
index b9fb10e..9fe5c01 100644
--- a/usr.sbin/makefs/makefs.8
+++ b/usr.sbin/makefs/makefs.8
@@ -40,7 +40,7 @@
 .Os
 .Sh NAME
 .Nm makefs
-.Nd create a file system image from a directory tree
+.Nd create a file system image from a directory tree or a mtree manifest
 .Sh SYNOPSIS
 .Nm
 .Op Fl x
@@ -57,14 +57,16 @@
 .Op Fl s Ar image-size
 .Op Fl t Ar fs-type
 .Ar image-file
-.Ar directory
+.Ar directory | manifest
 .Sh DESCRIPTION
 The utility
 .Nm
 creates a file system image into
 .Ar image-file
 from the directory tree
-.Ar directory .
+.Ar directory
+or from the mtree manifest
+.Ar manifest .
 No special devices or privileges are required to perform this task.
 .Pp
 The options are as follows:
@@ -106,6 +108,8 @@ as an
 .Xr mtree 8
 .Sq specfile
 specification.
+This option has no effect when the image is created from a mtree manifest
+rather than a directory.
 .Pp
 If a specfile entry exists in the underlying file system, its
 permissions and modification time will be used unless specifically
@@ -330,6 +334,7 @@ Use RockRidge extensions (for longer filenames, etc.).
 Volume set identifier of the image.
 .El
 .Sh SEE ALSO
+.Xr mtree 5 ,
 .Xr mtree 8 ,
 .Xr newfs 8
 .Sh HISTORY
diff --git a/usr.sbin/makefs/makefs.c b/usr.sbin/makefs/makefs.c
index 60b6916..a186014 100644
--- a/usr.sbin/makefs/makefs.c
+++ b/usr.sbin/makefs/makefs.c
@@ -38,6 +38,8 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <sys/types.h>
+#include <sys/stat.h>
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
@@ -80,11 +82,13 @@ int		main(int, char *[]);
 int
 main(int argc, char *argv[])
 {
+	struct stat	 sb;
 	struct timeval	 start;
 	fstype_t	*fstype;
 	fsinfo_t	 fsoptions;
 	fsnode		*root;
 	int	 	 ch, len;
+	char		*subtree;
 	char		*specfile;
 
 	setprogname(argv[0]);
@@ -244,26 +248,47 @@ main(int argc, char *argv[])
 	if (fsoptions.onlyspec != 0 && specfile == NULL)
 		errx(1, "-x requires -F mtree-specfile.");
 
-				/* walk the tree */
-	TIMER_START(start);
-	root = walk_dir(argv[1], NULL);
-	TIMER_RESULTS(start, "walk_dir");
+	/* Accept '-' as meaning "read from standard input". */
+	if (strcmp(argv[1], "-") == 0)
+		sb.st_mode = S_IFREG;
+	else {
+		if (stat(argv[1], &sb) == -1)
+			err(1, "Can't stat `%s'", argv[1]);
+	}
+
+	switch (sb.st_mode & S_IFMT) {
+	case S_IFDIR:		/* walk the tree */
+		subtree = argv[1];
+		TIMER_START(start);
+		root = walk_dir(subtree, NULL);
+		TIMER_RESULTS(start, "walk_dir");
+		break;
+	case S_IFREG:		/* read the manifest file */
+		subtree = ".";
+		TIMER_START(start);
+		root = read_mtree(argv[1], NULL);
+		TIMER_RESULTS(start, "manifest");
+		break;
+	default:
+		errx(1, "%s: not a file or directory", argv[1]);
+		/* NOTREACHED */
+	}
 
 	if (specfile) {		/* apply a specfile */
 		TIMER_START(start);
-		apply_specfile(specfile, argv[1], root, fsoptions.onlyspec);
+		apply_specfile(specfile, subtree, root, fsoptions.onlyspec);
 		TIMER_RESULTS(start, "apply_specfile");
 	}
 
 	if (debug & DEBUG_DUMP_FSNODES) {
-		printf("\nparent: %s\n", argv[1]);
+		printf("\nparent: %s\n", subtree);
 		dump_fsnodes(".", root);
 		putchar('\n');
 	}
 
 				/* build the file system */
 	TIMER_START(start);
-	fstype->make_fs(argv[0], argv[1], root, &fsoptions);
+	fstype->make_fs(argv[0], subtree, root, &fsoptions);
 	TIMER_RESULTS(start, "make_fs");
 
 	free_fsnodes(root);
@@ -311,7 +336,7 @@ usage(void)
 "usage: %s [-t fs-type] [-o fs-options] [-d debug-mask] [-B endian]\n"
 "\t[-S sector-size] [-M minimum-size] [-m maximum-size] [-s image-size]\n"
 "\t[-b free-blocks] [-f free-files] [-F mtree-specfile] [-x]\n"
-"\t[-N userdb-dir] image-file directory\n",
+"\t[-N userdb-dir] image-file directory | manifest\n",
 	    prog);
 	exit(1);
 }
diff --git a/usr.sbin/makefs/makefs.h b/usr.sbin/makefs/makefs.h
index 997c4db..6556ec0 100644
--- a/usr.sbin/makefs/makefs.h
+++ b/usr.sbin/makefs/makefs.h
@@ -93,11 +93,13 @@ typedef struct _fsnode {
 	uint32_t	 type;		/* type of entry */
 	fsinode		*inode;		/* actual inode data */
 	char		*symlink;	/* symlink target */
+	char		*contents;	/* file to provide contents */
 	char		*name;		/* file name */
 	int		flags;		/* misc flags */
 } fsnode;
 
 #define	FSNODE_F_HASSPEC	0x01	/* fsnode has a spec entry */
+#define	FSNODE_F_OPTIONAL	0x02	/* fsnode is optional */
 
 /*
  * fsinfo_t - contains various settings and parameters pertaining to
@@ -147,6 +149,7 @@ typedef struct {
 void		apply_specfile(const char *, const char *, fsnode *, int);
 void		dump_fsnodes(const char *, fsnode *);
 const char *	inode_type(mode_t);
+fsnode *	read_mtree(const char *, fsnode *);
 int		set_option(option_t *, const char *, const char *);
 fsnode *	walk_dir(const char *, fsnode *);
 void		free_fsnodes(fsnode *);
diff --git a/usr.sbin/makefs/mtree.c b/usr.sbin/makefs/mtree.c
new file mode 100644
index 0000000..5d88ad6
--- /dev/null
+++ b/usr.sbin/makefs/mtree.c
@@ -0,0 +1,1051 @@
+/*-
+ * Copyright (c) 2011 Marcel Moolenaar
+ * 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 <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/queue.h>
+#include <sys/sbuf.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <inttypes.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+
+#include "makefs.h"
+
+#define	IS_DOT(nm)	((nm)[0] == '.' && (nm)[1] == '\0')
+#define	IS_DOTDOT(nm)	((nm)[0] == '.' && (nm)[1] == '.' && (nm)[2] == '\0')
+
+struct mtree_fileinfo {
+	SLIST_ENTRY(mtree_fileinfo) next;
+	FILE *fp;
+	const char *name;
+	u_int line;
+};
+
+/* Global state used while parsing. */
+static SLIST_HEAD(, mtree_fileinfo) mtree_fileinfo =
+    SLIST_HEAD_INITIALIZER(mtree_fileinfo);
+static fsnode *mtree_root;
+static fsnode *mtree_current;
+static fsnode mtree_global;
+static fsinode mtree_global_inode;
+static u_int errors, warnings;
+
+static void mtree_error(const char *, ...) __printflike(1, 2);
+static void mtree_warning(const char *, ...) __printflike(1, 2);
+
+static int
+mtree_file_push(const char *name, FILE *fp)
+{
+	struct mtree_fileinfo *fi;
+
+	fi = malloc(sizeof(*fi));
+	if (fi == NULL)
+		return (ENOMEM);
+
+	if (strcmp(name, "-") == 0)
+		fi->name = strdup("(stdin)");
+	else
+		fi->name = strdup(name);
+	if (fi->name == NULL) {
+		free(fi);
+		return (ENOMEM);
+	}
+
+	fi->fp = fp;
+	fi->line = 0;
+
+	SLIST_INSERT_HEAD(&mtree_fileinfo, fi, next);
+	return (0);
+}
+
+static void
+mtree_print(const char *msgtype, const char *fmt, va_list ap)
+{
+	struct mtree_fileinfo *fi;
+
+	if (msgtype != NULL) {
+		fi = SLIST_FIRST(&mtree_fileinfo);
+		if (fi != NULL)
+			fprintf(stderr, "%s:%u: ", fi->name, fi->line);
+		fprintf(stderr, "%s: ", msgtype);
+	}
+	vfprintf(stderr, fmt, ap);
+}
+
+static void
+mtree_error(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	mtree_print("error", fmt, ap);
+	va_end(ap);
+
+	errors++;
+	fputc('\n', stderr);
+}
+
+static void
+mtree_warning(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	mtree_print("warning", fmt, ap);
+	va_end(ap);
+
+	warnings++;
+	fputc('\n', stderr);
+}
+
+/* mtree_resolve() sets errno to indicate why NULL was returned. */
+static char *
+mtree_resolve(const char *spec, int *istemp)
+{
+	struct sbuf *sb;
+	char *res, *var;
+	const char *base, *p, *v;
+	size_t len;
+	int c, error, quoted, subst;
+
+	len = strlen(spec);
+	if (len == 0) {
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	c = (len > 1) ? (spec[0] == spec[len - 1]) ? spec[0] : 0 : 0;
+	*istemp = (c == '`') ? 1 : 0;
+	subst = (c == '`' || c == '"') ? 1 : 0;
+	quoted = (subst || c == '\'') ? 1 : 0;
+
+	if (!subst) {
+		res = strdup(spec + quoted);
+		if (res != NULL && quoted)
+			res[len - 2] = '\0';
+		return (res);
+	}
+
+	sb = sbuf_new_auto();
+	if (sb == NULL) {
+		errno = ENOMEM;
+		return (NULL);
+	}
+
+	base = spec + 1;
+	len -= 2;
+	error = 0;
+	while (len > 0) {
+		p = strchr(base, '$');
+		if (p == NULL) {
+			sbuf_bcat(sb, base, len);
+			base += len;
+			len = 0;
+			continue;
+		}
+		/* The following is safe. spec always starts with a quote. */
+		if (p[-1] == '\\')
+			p--;
+		if (base != p) {
+			sbuf_bcat(sb, base, p - base);
+			len -= p - base;
+			base = p;
+		}
+		if (*p == '\\') {
+			sbuf_putc(sb, '$');
+			base += 2;
+			len -= 2;
+			continue;
+		}
+		/* Skip the '$'. */
+		base++;
+		len--;
+		/* Handle ${X} vs $X. */
+		v = base;
+		if (*base == '{') {
+			p = strchr(v, '}');
+			if (p == NULL)
+				p = v;
+		} else
+			p = v;
+		len -= (p + 1) - base;
+		base = p + 1;
+
+		if (v == p) {
+			sbuf_putc(sb, *v);
+			continue;
+		}
+
+		error = ENOMEM;
+		var = calloc(p - v, 1);
+		if (var == NULL)
+			break;
+
+		memcpy(var, v + 1, p - v - 1);
+		if (strcmp(var, ".CURDIR") == 0) {
+			res = getcwd(NULL, 0);
+			if (res == NULL)
+				break;
+		} else if (strcmp(var, ".PROG") == 0) {
+			res = strdup(getprogname());
+			if (res == NULL)
+				break;
+		} else {
+			v = getenv(var);
+			if (v != NULL) {
+				res = strdup(v);
+				if (res == NULL)
+					break;
+			} else
+				res = NULL;
+		}
+		error = 0;
+
+		if (res != NULL) {
+			sbuf_cat(sb, res);
+			free(res);
+		}
+		free(var);
+	}
+
+	sbuf_finish(sb);
+	res = (error == 0) ? strdup(sbuf_data(sb)) : NULL;
+	sbuf_delete(sb);
+	if (res == NULL)
+		errno = ENOMEM;
+	return (res);
+}
+
+static int
+skip_over(FILE *fp, const char *cs)
+{
+	int c;
+
+	c = getc(fp);
+	while (c != EOF && strchr(cs, c) != NULL)
+		c = getc(fp);
+	if (c != EOF) {
+		ungetc(c, fp);
+		return (0);
+	}
+	return (ferror(fp) ? errno : -1);
+}
+
+static int
+skip_to(FILE *fp, const char *cs)
+{
+	int c;
+
+	c = getc(fp);
+	while (c != EOF && strchr(cs, c) == NULL)
+		c = getc(fp);
+	if (c != EOF) {
+		ungetc(c, fp);
+		return (0);
+	}
+	return (ferror(fp) ? errno : -1);
+}
+
+static int
+read_word(FILE *fp, char *buf, size_t bufsz)
+{
+	struct mtree_fileinfo *fi;
+	size_t idx, qidx;
+	int c, done, error, esc, qlvl;
+
+	if (bufsz == 0)
+		return (EINVAL);
+
+	done = 0;
+	esc = 0;
+	idx = 0;
+	qidx = -1;
+	qlvl = 0;
+	do {
+		c = getc(fp);
+		switch (c) {
+		case EOF:
+			buf[idx] = '\0';
+			error = ferror(fp) ? errno : -1;
+			if (error == -1)
+				mtree_error("unexpected end of file");
+			return (error);
+		case '\\':
+			esc++;
+			if (esc == 1)
+				continue;
+			break;
+		case '`':
+		case '\'':
+		case '"':
+			if (esc)
+				break;
+			if (qlvl == 0) {
+				qlvl++;
+				qidx = idx;
+			} else if (c == buf[qidx]) {
+				qlvl--;
+				if (qlvl > 0) {
+					do {
+						qidx--;
+					} while (buf[qidx] != '`' &&
+					    buf[qidx] != '\'' &&
+					    buf[qidx] != '"');
+				} else
+					qidx = -1;
+			} else {
+				qlvl++;
+				qidx = idx;
+			}
+			break;
+		case ' ':
+		case '\t':
+		case '\n':
+			if (!esc && qlvl == 0) {
+				ungetc(c, fp);
+				c = '\0';
+				done = 1;
+				break;
+			}
+			if (c == '\n') {
+				/*
+				 * We going to eat the newline ourselves.
+				 */
+				if (qlvl > 0)
+					mtree_warning("quoted word straddles "
+					    "onto next line.");
+				fi = SLIST_FIRST(&mtree_fileinfo);
+				fi->line++;
+			}
+			break;
+		case 'a':
+			if (esc)
+				c = '\a';
+			break;
+		case 'b':
+			if (esc)
+				c = '\b';
+			break;
+		case 'f':
+			if (esc)
+				c = '\f';
+			break;
+		case 'n':
+			if (esc)
+				c = '\n';
+			break;
+		case 'r':
+			if (esc)
+				c = '\r';
+			break;
+		case 't':
+			if (esc)
+				c = '\t';
+			break;
+		case 'v':
+			if (esc)
+				c = '\v';
+			break;
+		}
+		buf[idx++] = c;
+		esc = 0;
+	} while (idx < bufsz && !done);
+
+	if (idx >= bufsz) {
+		mtree_error("word too long to fit buffer (max %zu characters)",
+		    bufsz);
+		skip_to(fp, " \t\n");
+	}
+	return (0);
+}
+
+static fsnode *
+create_node(const char *name, u_int type, fsnode *parent, fsnode *global)
+{
+	fsnode *n;
+
+	n = calloc(1, sizeof(*n));
+	if (n == NULL)
+		return (NULL);
+
+	n->name = strdup(name);
+	if (n->name == NULL) {
+		free(n);
+		return (NULL);
+	}
+
+	n->type = (type == 0) ? global->type : type;
+	n->parent = parent;
+
+	n->inode = calloc(1, sizeof(*n->inode));
+	if (n->inode == NULL) {
+		free(n->name);
+		free(n);
+		return (NULL);
+	}
+
+	/* Assign global options/defaults. */
+	bcopy(global->inode, n->inode, sizeof(*n->inode));
+	n->inode->st.st_mode = (n->inode->st.st_mode & ~S_IFMT) | n->type;
+
+	if (n->type == S_IFLNK)
+		n->symlink = global->symlink;
+	else if (n->type == S_IFREG)
+		n->contents = global->contents;
+
+	return (n);
+}
+
+static void
+destroy_node(fsnode *n)
+{
+
+	assert(n != NULL);
+	assert(n->name != NULL);
+	assert(n->inode != NULL);
+
+	free(n->inode);
+	free(n->name);
+	free(n);
+}
+
+static int
+read_number(const char *tok, u_int base, intmax_t *res, intmax_t min,
+    intmax_t max)
+{
+	char *end;
+	intmax_t val;
+
+	val = strtoimax(tok, &end, base);
+	if (end == tok || end[0] != '\0')
+		return (EINVAL);
+	if (val < min || val > max)
+		return (EDOM);
+	*res = val;
+	return (0);
+}
+
+static int
+read_mtree_keywords(FILE *fp, fsnode *node)
+{
+	char keyword[PATH_MAX];
+	char *name, *p, *value;
+	struct group *grent;
+	struct passwd *pwent;
+	struct stat *st, sb;
+	intmax_t num;
+	u_long flset, flclr;
+	int error, istemp, type;
+
+	st = &node->inode->st;
+	do {
+		error = skip_over(fp, " \t");
+		if (error)
+			break;
+
+		error = read_word(fp, keyword, sizeof(keyword));
+		if (error)
+			break;
+
+		if (keyword[0] == '\0')
+			break;
+
+		value = strchr(keyword, '=');
+		if (value != NULL)
+			*value++ = '\0';
+
+		/*
+		 * We use EINVAL, ENOATTR, ENOSYS and ENXIO to signal
+		 * certain conditions:
+		 *   EINVAL -	Value provided for a keyword that does
+		 *		not take a value. The value is ignored.
+		 *   ENOATTR -	Value missing for a keyword that needs
+		 *		a value. The keyword is ignored.
+		 *   ENOSYS -	Unsupported keyword encountered. The
+		 *		keyword is ignored.
+		 *   ENXIO -	Value provided for a keyword that does
+		 *		not take a value. The value is ignored.
+		 */
+		switch (keyword[0]) {
+		case 'c':
+			if (strcmp(keyword, "contents") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				node->contents = strdup(value);
+			} else
+				error = ENOSYS;
+			break;
+		case 'f':
+			if (strcmp(keyword, "flags") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				flset = flclr = 0;
+				if (!strtofflags(&value, &flset, &flclr)) {
+					st->st_flags &= ~flclr;
+					st->st_flags |= flset;
+				} else
+					error = errno;
+			} else
+				error = ENOSYS;
+			break;
+		case 'g':
+			if (strcmp(keyword, "gid") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				error = read_number(value, 10, &num,
+				    0, UINT_MAX);
+				if (!error)
+					st->st_gid = num;
+			} else if (strcmp(keyword, "gname") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				grent = getgrnam(value);
+				if (grent != NULL)
+					st->st_gid = grent->gr_gid;
+				else
+					error = errno;
+			} else
+				error = ENOSYS;
+			break;
+		case 'l':
+			if (strcmp(keyword, "link") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				node->symlink = strdup(value);
+			} else
+				error = ENOSYS;
+			break;
+		case 'm':
+			if (strcmp(keyword, "mode") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				if (value[0] >= '0' && value[0] <= '9') {
+					error = read_number(value, 8, &num,
+					    0, 07777);
+					if (!error) {
+						st->st_mode &= S_IFMT;
+						st->st_mode |= num;
+					}
+				} else {
+					/* Symbolic mode not supported. */
+					error = EINVAL;
+					break;
+				}
+			} else
+				error = ENOSYS;
+			break;
+		case 'o':
+			if (strcmp(keyword, "optional") == 0) {
+				if (value != NULL)
+					error = ENXIO;
+				node->flags |= FSNODE_F_OPTIONAL;
+			} else
+				error = ENOSYS;
+			break;
+		case 's':
+			if (strcmp(keyword, "size") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				error = read_number(value, 10, &num,
+				    0, INTMAX_MAX);
+				if (!error)
+					st->st_size = num;
+			} else
+				error = ENOSYS;
+			break;
+		case 't':
+			if (strcmp(keyword, "time") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				p = strchr(value, '.');
+				if (p != NULL)
+					*p++ = '\0';
+				error = read_number(value, 10, &num, 0,
+				    INTMAX_MAX);
+				if (error)
+					break;
+				st->st_atime = num;
+				st->st_ctime = num;
+				st->st_mtime = num;
+				error = read_number(p, 10, &num, 0,
+				    INTMAX_MAX);
+				if (error)
+					break;
+				if (num != 0)
+					error = EINVAL;
+			} else if (strcmp(keyword, "type") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				if (strcmp(value, "dir") == 0)
+					node->type = S_IFDIR;
+				else if (strcmp(value, "file") == 0)
+					node->type = S_IFREG;
+				else if (strcmp(value, "link") == 0)
+					node->type = S_IFLNK;
+				else
+					error = EINVAL;
+			} else
+				error = ENOSYS;
+			break;
+		case 'u':
+			if (strcmp(keyword, "uid") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				error = read_number(value, 10, &num,
+				    0, UINT_MAX);
+				if (!error)
+					st->st_uid = num;
+			} else if (strcmp(keyword, "uname") == 0) {
+				if (value == NULL) {
+					error = ENOATTR;
+					break;
+				}
+				pwent = getpwnam(value);
+				if (pwent != NULL)
+					st->st_uid = pwent->pw_uid;
+				else
+					error = errno;
+			} else
+				error = ENOSYS;
+			break;
+		default:
+			error = ENOSYS;
+			break;
+		}
+
+		switch (error) {
+		case EINVAL:
+			mtree_error("%s: invalid value '%s'", keyword, value);
+			break;
+		case ENOATTR:
+			mtree_error("%s: keyword needs a value", keyword);
+			break;
+		case ENOSYS:
+			mtree_warning("%s: unsupported keyword", keyword);
+			break;
+		case ENXIO:
+			mtree_error("%s: keyword does not take a value",
+			    keyword);
+			break;
+		}
+	} while (1);
+
+	if (error)
+		return (error);
+
+	st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
+
+	/* Nothing more to do for the global defaults. */
+	if (node->name == NULL)
+		return (0);
+
+	/*
+	 * Be intelligent about the file type.
+	 */
+	if (node->contents != NULL) {
+		if (node->symlink != NULL) {
+			mtree_error("%s: both link and contents keywords "
+			    "defined", node->name);
+			return (0);
+		}
+		type = S_IFREG;
+	} else
+		type = (node->symlink != NULL) ? S_IFLNK : S_IFDIR;
+
+	if (node->type == 0)
+		node->type = type;
+
+	if (node->type != type) {
+		mtree_error("%s: file type and defined keywords to not match",
+		    node->name);
+		return (0);
+	}
+
+	st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
+
+	if (node->contents == NULL)
+		return (0);
+
+	name = mtree_resolve(node->contents, &istemp);
+	if (name == NULL)
+		return (errno);
+
+	if (stat(name, &sb) != 0) {
+		mtree_error("%s: contents file '%s' not found", node->name,
+		    name);
+		free(name);
+		return (0);
+	}
+
+	free(node->contents);
+	node->contents = name;
+	st->st_size = sb.st_size;
+	return (0);
+}
+
+static int
+read_mtree_command(FILE *fp)
+{
+	char cmd[10];
+	int error;
+
+	error = read_word(fp, cmd, sizeof(cmd));
+	if (error)
+		goto out;
+
+	error = read_mtree_keywords(fp, &mtree_global);
+
+ out:
+	skip_to(fp, "\n");
+	(void)getc(fp);
+	return (error);
+}
+
+static int
+read_mtree_spec1(FILE *fp, bool def, const char *name)
+{
+	fsnode *last, *node, *parent;
+	u_int type;
+	int error;
+
+	assert(name[0] != '\0');
+
+	/*
+	 * Treat '..' specially, because it only changes our current
+	 * directory. We don't create a node for it. We simply ignore
+	 * any keywords that may appear on the line as well.
+	 * Going up a directory is a little non-obvious. A directory
+	 * node has a corresponding '.' child. The parent of '.' is
+	 * not the '.' node of the parent directory, but the directory
+	 * node within the parent to which the child relates. However,
+	 * going up a directory means we need to find the '.' node to
+	 * which the directoy node is linked.  This we can do via the
+	 * first * pointer, because '.' is always the first entry in a
+	 * directory.
+	 */
+	if (IS_DOTDOT(name)) {
+		/* This deals with NULL pointers as well. */
+		if (mtree_current == mtree_root) {
+			mtree_warning("ignoring .. in root directory");
+			return (0);
+		}
+
+		node = mtree_current;
+
+		assert(node != NULL);
+		assert(IS_DOT(node->name));
+		assert(node->first == node);
+
+		/* Get the corresponding directory node in the parent. */
+		node = mtree_current->parent;
+
+		assert(node != NULL);
+		assert(!IS_DOT(node->name));
+
+		node = node->first;
+
+		assert(node != NULL);
+		assert(IS_DOT(node->name));
+		assert(node->first == node);
+
+		mtree_current = node;
+		return (0);
+	}
+
+	/*
+	 * If we don't have a current directory and the first specification
+	 * (either implicit or defined) is not '.', then we need to create
+	 * a '.' node first (using a recursive call).
+	 */
+	if (!IS_DOT(name) && mtree_current == NULL) {
+		error = read_mtree_spec1(fp, false, ".");
+		if (error)
+			return (error);
+	}
+
+	/*
+	 * Lookup the name in the current directory (if we have a current
+	 * directory) to make sure we do not create multiple nodes for the
+	 * same component. For non-definitions, if we find a node with the
+	 * same name, simply change the current directory. For definitions
+	 * more happens.
+	 */
+	last = NULL;
+	node = mtree_current;
+	while (node != NULL) {
+		assert(node->first == mtree_current);
+
+		if (strcmp(name, node->name) == 0) {
+			if (def == true) {
+				mtree_error("duplicate definition of %s",
+				    name);
+				return (0);
+			}
+
+			if (node->type != S_IFDIR) {
+				mtree_error("%s is not a directory", name);
+				return (0);
+			}
+
+			assert(!IS_DOT(name));
+
+			node = node->child;
+
+			assert(node != NULL);
+			assert(IS_DOT(node->name));
+
+			mtree_current = node;
+			return (0);
+		}
+
+		last = node;
+		node = last->next;
+	}
+
+	parent = (mtree_current != NULL) ? mtree_current->parent : NULL;
+	type = (def == false || IS_DOT(name)) ? S_IFDIR : 0;
+	node = create_node(name, type, parent, &mtree_global);
+	if (node == NULL)
+		return (ENOMEM);
+
+	if (def == true) {
+		error = read_mtree_keywords(fp, node);
+		if (error) {
+			destroy_node(node);
+			return (error);
+		}
+	}
+
+	node->first = (mtree_current != NULL) ? mtree_current : node;
+
+	if (last != NULL)
+		last->next = node;
+
+	if (node->type != S_IFDIR)
+		return (0);
+
+	if (!IS_DOT(node->name)) {
+		parent = node;
+		node = create_node(".", S_IFDIR, parent, parent);
+		if (node == NULL) {
+			last->next = NULL;
+			destroy_node(parent);
+			return (ENOMEM);
+		}
+		parent->child = node;
+		node->first = node;
+	}
+
+	assert(node != NULL);
+	assert(IS_DOT(node->name));
+	assert(node->first == node);
+
+	mtree_current = node;
+	if (mtree_root == NULL)
+		mtree_root = node;
+
+	return (0);
+}
+
+static int
+read_mtree_spec(FILE *fp)
+{
+	char pathspec[PATH_MAX];
+	char *cp;
+	int error;
+
+	error = read_word(fp, pathspec, sizeof(pathspec));
+	if (error)
+		goto out;
+
+	cp = strchr(pathspec, '/');
+	if (cp != NULL) {
+		/* Absolute pathname */
+		mtree_current = mtree_root;
+
+		do {
+			*cp++ = '\0';
+
+			/* Disallow '.' and '..' as components. */
+			if (IS_DOT(pathspec) || IS_DOTDOT(pathspec)) {
+				mtree_error("absolute path cannot contain . "
+				    "or .. components");
+				goto out;
+			}
+
+			/* Ignore multiple adjacent slashes. */
+			if (pathspec[0] != '\0')
+				error = read_mtree_spec1(fp, false, pathspec);
+			memmove(pathspec, cp, strlen(cp) + 1);
+			cp = strchr(pathspec, '/');
+		} while (!error && cp != NULL);
+
+		/* Disallow '.' and '..' as the last component. */
+		if (!error && (IS_DOT(pathspec) || IS_DOTDOT(pathspec))) {
+			mtree_error("absolute path cannot contain . or .. "
+			    "components");
+			goto out;
+		}
+	}
+
+	/* Ignore absolute specfications that end with a slash. */
+	if (!error && pathspec[0] != '\0')
+		error = read_mtree_spec1(fp, true, pathspec);
+
+ out:
+	skip_to(fp, "\n");
+	(void)getc(fp);
+	return (error);
+}
+
+fsnode *
+read_mtree(const char *fname, fsnode *node)
+{
+	struct mtree_fileinfo *fi;
+	FILE *fp;
+	int c, error;
+
+	/* We do not yet support nesting... */
+	assert(node == NULL);
+
+	if (strcmp(fname, "-") == 0)
+		fp = stdin;
+	else {
+		fp = fopen(fname, "r");
+		if (fp == NULL)
+			err(1, "Can't open `%s'", fname);
+	}
+
+	error = mtree_file_push(fname, fp);
+	if (error)
+		goto out;
+
+	bzero(&mtree_global, sizeof(mtree_global));
+	bzero(&mtree_global_inode, sizeof(mtree_global_inode));
+	mtree_global.inode = &mtree_global_inode;
+	mtree_global_inode.nlink = 1;
+	mtree_global_inode.st.st_atime = mtree_global_inode.st.st_ctime =
+	    mtree_global_inode.st.st_mtime = time(NULL);
+	errors = warnings = 0;
+
+	setgroupent(1);
+	setpassent(1);
+
+	mtree_root = node;
+	mtree_current = node;
+	do {
+		/* Start of a new line... */
+		fi = SLIST_FIRST(&mtree_fileinfo);
+		fi->line++;
+
+		error = skip_over(fp, " \t");
+		if (error)
+			break;
+
+		c = getc(fp);
+		if (c == EOF) {
+			error = ferror(fp) ? errno : -1;
+			break;
+		}
+
+		switch (c) {
+		case '\n':		/* empty line */
+			error = 0;
+			break;
+		case '#':		/* comment -- skip to end of line. */
+			error = skip_to(fp, "\n");
+			if (!error)
+				(void)getc(fp);
+			break;
+		case '/':		/* special commands */
+			error = read_mtree_command(fp);
+			break;
+		default:		/* specification */
+			ungetc(c, fp);
+			error = read_mtree_spec(fp);
+			break;
+		}
+	} while (!error);
+
+	endpwent();
+	endgrent();
+
+	if (error <= 0 && (errors || warnings)) {
+		warnx("%u error(s) and %u warning(s) in mtree manifest",
+		    errors, warnings);
+		if (errors)
+			exit(1);
+	}
+
+ out:
+	if (error > 0)
+		errc(1, error, "Error reading mtree file");
+
+	if (fp != stdin)
+		fclose(fp);
+
+	if (mtree_root != NULL)
+		return (mtree_root);
+
+	/* Handle empty specifications. */
+	node = create_node(".", S_IFDIR, NULL, &mtree_global);
+	node->first = node;
+	return (node);
+}