1 files changed, 352 insertions, 0 deletions
diff --git a/support/junction/path.c b/support/junction/path.c
new file mode 100644
index 0000000..13a1438
--- /dev/null
+++ b/support/junction/path.c
@@ -0,0 +1,352 @@
+/**
+ * @file support/junction/path.c
+ * @brief Encode and decode FedFS pathnames
+ */
+
+/*
+ * Copyright 2010, 2011, 2018 Oracle.  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 version 2.0 as
+ * published by the Free Software Foundation.
+ *
+ * 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 version 2.0 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2.0 along with nfs-utils.  If not, see:
+ *
+ *	http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <stdbool.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <dirent.h>
+
+#include <netinet/in.h>
+
+#include "junction.h"
+#include "xlog.h"
+
+#define STRLEN_SLASH	((size_t)1)	/* strlen("/") */
+
+#define XDR_UINT_BYTES	(sizeof(uint32_t))
+
+/**
+ * Compute count of XDR 4-octet units from byte count
+ *
+ * @param bytes number of bytes to convert
+ * @return equivalent number of XDR 4-octet units
+ */
+static inline size_t
+nsdb_quadlen(size_t bytes)
+{
+	return (bytes + 3) >> 2;
+}
+
+/**
+ * Free array of NUL-terminated C strings
+ *
+ * @param strings array of char * to be released
+ */
+void
+nsdb_free_string_array(char **strings)
+{
+	int i;
+
+	if (strings == NULL)
+		return;
+	for (i = 0; strings[i] != NULL; i++)
+		free(strings[i]);
+	free(strings);
+}
+
+static FedFsStatus
+nsdb_alloc_zero_component_pathname(char ***path_array)
+{
+	char **result;
+
+	xlog(D_GENERAL, "%s: Zero-component pathname", __func__);
+
+	result = (char **)calloc(1, sizeof(char *));
+	if (result == NULL)
+		return FEDFS_ERR_SVRFAULT;
+	result[0] = NULL;
+	*path_array = result;
+	return FEDFS_OK;
+}
+
+/**
+ * Sanitize an incoming POSIX path
+ *
+ * @param pathname NUL-terminated C string containing a POSIX pathname
+ * @return NUL-terminated C string containing sanitized path
+ *
+ * Caller must free the returned pathname with free(3).
+ *
+ * Remove multiple sequential slashes and any trailing slashes,
+ * but leave "/" by itself alone.
+ */
+static __attribute_malloc__ char *
+nsdb_normalize_path(const char *pathname)
+{
+	size_t i, j, len;
+	char *result;
+
+	len = strlen(pathname);
+	if (len == 0) {
+		xlog(D_CALL, "%s: NULL pathname", __func__);
+		return NULL;
+	}
+
+	result = malloc(len + 1);
+	if (result == NULL)
+		return NULL;
+
+	for (i = 0, j = 0; i < len; i++) {
+		if (pathname[i] == '/' && pathname[i + 1] == '/')
+			continue;
+		result[j++] = pathname[i];
+	}
+	result[j] = '\0';
+
+	if (j > 1 && result[j - 1] == '/')
+		result[j - 1] = '\0';
+
+	xlog(D_CALL, "%s: result = '%s'", __func__, result);
+	return result;
+}
+
+/**
+ * Count the number of components in a POSIX pathname
+ *
+ * @param pathname NUL-terminated C string containing a POSIX pathname
+ * @param len OUT: number of bytes the encoded XDR stream will consume
+ * @param cnt OUT: component count
+ * @return true when successful
+ */
+static _Bool
+nsdb_count_components(const char *pathname, size_t *len,
+		unsigned int *cnt)
+{
+	char *start, *component;
+	unsigned int count;
+	size_t length;
+
+	/* strtok(3) will tromp on the string */
+	start = strdup(pathname);
+	if (start == NULL)
+		return false;
+
+	length = XDR_UINT_BYTES;
+	count = 0;
+	component = start;
+	for ( ;; ) {
+		char *next;
+		size_t tmp;
+
+		if (*component == '/')
+			component++;
+		if (*component == '\0')
+			break;
+		next = strchrnul(component, '/');
+		tmp = (size_t)(next - component);
+		if (tmp > 255) {
+			free(start);
+			return false;
+		}
+		length += XDR_UINT_BYTES + (nsdb_quadlen(tmp) << 2);
+		count++;
+
+		if (*next == '\0')
+			break;
+		component = next;
+	}
+
+	free(start);
+
+	xlog(D_CALL, "%s: length = %zu, count = %u, path = '%s'",
+		__func__, length, count, pathname);
+	*len = length;
+	*cnt = count;
+	return true;
+}
+
+/**
+ * Predicate: is input character set for a POSIX pathname valid UTF-8?
+ *
+ * @param pathname NUL-terminated C string containing a POSIX path
+ * @return true if the string is valid UTF-8
+ *
+ * XXX: implement this
+ */
+static _Bool
+nsdb_pathname_is_utf8(__attribute__((unused)) const char *pathname)
+{
+	return true;
+}
+
+/**
+ * Construct a local POSIX-style pathname from an array of component strings
+ *
+ * @param path_array array of pointers to NUL-terminated C strings
+ * @param pathname OUT: pointer to NUL-terminated UTF-8 C string containing a POSIX-style path
+ * @return a FedFsStatus code
+ *
+ * Caller must free the returned pathname with free(3).
+ */
+FedFsStatus
+nsdb_path_array_to_posix(char * const *path_array, char **pathname)
+{
+	char *component, *result;
+	unsigned int i, count;
+	size_t length, len;
+
+	if (path_array == NULL || pathname == NULL)
+		return FEDFS_ERR_INVAL;
+
+	if (path_array[0] == NULL) {
+		xlog(D_GENERAL, "%s: Zero-component pathname", __func__);
+		result = strdup("/");
+		if (result == NULL)
+			return FEDFS_ERR_SVRFAULT;
+		*pathname = result;
+		return FEDFS_OK;
+	}
+
+	for (length = 0, count = 0;
+	     path_array[count] != NULL;
+	     count++) {
+		component = path_array[count];
+		len = strlen(component);
+
+		if (len == 0) {
+			xlog(D_GENERAL, "%s: Zero-length component", __func__);
+			return FEDFS_ERR_BADNAME;
+		}
+		if (len > NAME_MAX) {
+			xlog(D_GENERAL, "%s: Component length too long", __func__);
+			return FEDFS_ERR_NAMETOOLONG;
+		}
+		if (strchr(component, '/') != NULL) {
+			xlog(D_GENERAL, "%s: Local separator character "
+					"found in component", __func__);
+			return FEDFS_ERR_BADNAME;
+		}
+		if (!nsdb_pathname_is_utf8(component)) {
+			xlog(D_GENERAL, "%s: Bad character in component",
+				__func__);
+			return FEDFS_ERR_BADCHAR;
+		}
+
+		length += STRLEN_SLASH + len;
+
+		if (length > PATH_MAX) {
+			xlog(D_GENERAL, "%s: Pathname too long", __func__);
+			return FEDFS_ERR_NAMETOOLONG;
+		}
+	}
+
+	result = calloc(1, length + 1);
+	if (result == NULL)
+		return FEDFS_ERR_SVRFAULT;
+
+	for (i = 0; i < count; i++) {
+		strcat(result, "/");
+		strcat(result, path_array[i]);
+	}
+	*pathname = nsdb_normalize_path(result);
+	free(result);
+	if (*pathname == NULL)
+		return FEDFS_ERR_SVRFAULT;
+	return FEDFS_OK;
+}
+
+/**
+ * Construct an array of component strings from a local POSIX-style pathname
+ *
+ * @param pathname NUL-terminated C string containing a POSIX-style pathname
+ * @param path_array OUT: pointer to array of pointers to NUL-terminated C strings
+ * @return a FedFsStatus code
+ *
+ * Caller must free "path_array" with nsdb_free_string_array().
+ */
+FedFsStatus
+nsdb_posix_to_path_array(const char *pathname, char ***path_array)
+{
+	char *normalized, *component, **result;
+	unsigned int i, count;
+	size_t length;
+
+	if (pathname == NULL || path_array == NULL)
+		return FEDFS_ERR_INVAL;
+
+	if (!nsdb_pathname_is_utf8(pathname)) {
+		xlog(D_GENERAL, "%s: Bad character in pathname", __func__);
+		return FEDFS_ERR_BADCHAR;
+	}
+
+	normalized = nsdb_normalize_path(pathname);
+	if (normalized == NULL)
+		return FEDFS_ERR_SVRFAULT;
+
+	if (!nsdb_count_components(normalized, &length, &count)) {
+		free(normalized);
+		return FEDFS_ERR_BADNAME;
+	}
+
+	if (count == 0) {
+		free(normalized);
+		return nsdb_alloc_zero_component_pathname(path_array);
+	}
+
+	result = (char **)calloc(count + 1, sizeof(char *));
+	if (result == NULL) {
+		free(normalized);
+		return FEDFS_ERR_SVRFAULT;
+	}
+
+	component = normalized;
+	for (i = 0; ; i++) {
+		char *next;
+
+		if (*component == '/')
+			component++;
+		if (*component == '\0')
+			break;
+		next = strchrnul(component, '/');
+		length = (size_t)(next - component);
+		if (length > 255) {
+			nsdb_free_string_array(result);
+			free(normalized);
+			return FEDFS_ERR_SVRFAULT;
+		}
+
+		result[i] = strndup(component, length);
+		if (result[i] == NULL) {
+			free(normalized);
+			nsdb_free_string_array(result);
+			return FEDFS_ERR_SVRFAULT;
+		}
+
+		if (*next == '\0')
+			break;
+		component = next;
+	}
+
+	*path_array = result;
+	free(normalized);
+	return FEDFS_OK;
+}