libnsm.a: refactor nsm_setup_pathnames() and nsm_make_pathname()

Move the logic in nsm_setup_pathnames() and nsm_make_pathname() to
similar generic functions in libmisc.a so that the exportfs and
rpc.mountd programs can make use of them later.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

2 files changed, 111 insertions, 1 deletions

diff --git a/support/misc/Makefile.am b/support/misc/Makefile.am
index 1048580..8936b0d 100644
--- a/support/misc/Makefile.am
+++ b/support/misc/Makefile.am
@@ -1,6 +1,6 @@
 ## Process this file with automake to produce Makefile.in
 
 noinst_LIBRARIES = libmisc.a
-libmisc_a_SOURCES = tcpwrapper.c from_local.c mountpoint.c
+libmisc_a_SOURCES = tcpwrapper.c from_local.c mountpoint.c file.c
 
 MAINTAINERCLEANFILES = Makefile.in
diff --git a/support/misc/file.c b/support/misc/file.c
new file mode 100644
index 0000000..63597df
--- /dev/null
+++ b/support/misc/file.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright 2009 Oracle.  All rights reserved.
+ * Copyright 2017 Red Hat, Inc.  All rights reserved.
+ *
+ * This file is part of nfs-utils.
+ *
+ * nfs-utils is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * nfs-utils is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with nfs-utils.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <sys/stat.h>
+
+#include <string.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <errno.h>
+#include <dirent.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "xlog.h"
+#include "misc.h"
+
+/*
+ * Returns a dynamically allocated, '\0'-terminated buffer
+ * containing an appropriate pathname, or NULL if an error
+ * occurs.  Caller must free the returned result with free(3).
+ */
+__attribute__((__malloc__))
+char *
+generic_make_pathname(const char *base, const char *leaf)
+{
+	size_t size;
+	char *path;
+	int len;
+
+	size = strlen(base) + strlen(leaf) + 2;
+	if (size > PATH_MAX)
+		return NULL;
+
+	path = malloc(size);
+	if (path == NULL)
+		return NULL;
+
+	len = snprintf(path, size, "%s/%s", base, leaf);
+	if ((len < 0) || ((size_t)len >= size)) {
+		free(path);
+		return NULL;
+	}
+
+	return path;
+}
+
+
+/**
+ * generic_setup_basedir - set up basedir
+ * @progname: C string containing name of program, for error messages
+ * @parentdir: C string containing pathname to on-disk state, or NULL
+ * @base: character buffer to contain the basedir that is set up
+ * @baselen: size of @base in bytes
+ *
+ * This runs before logging is set up, so error messages are directed
+ * to stderr.
+ *
+ * Returns true and sets up our basedir, if @parentdir was valid
+ * and usable; otherwise false is returned.
+ */
+_Bool
+generic_setup_basedir(const char *progname, const char *parentdir, char *base,
+		      const size_t baselen)
+{
+	static char buf[PATH_MAX];
+	struct stat st;
+	char *path;
+
+	/* First: test length of name and whether it exists */
+	if ((strlen(parentdir) >= baselen) || (strlen(parentdir) >= PATH_MAX)) {
+		(void)fprintf(stderr, "%s: Directory name too long: %s",
+				progname, parentdir);
+		return false;
+	}
+	if (lstat(parentdir, &st) == -1) {
+		(void)fprintf(stderr, "%s: Failed to stat %s: %s",
+				progname, parentdir, strerror(errno));
+		return false;
+	}
+
+	/* Ensure we have a clean directory pathname */
+	strncpy(buf, parentdir, sizeof(buf));
+	path = dirname(buf);
+	if (*path == '.') {
+		(void)fprintf(stderr, "%s: Unusable directory %s",
+				progname, parentdir);
+		return false;
+	}
+
+	xlog(D_CALL, "Using %s as the state directory", parentdir);
+	strcpy(base, parentdir);
+	return true;
+}