Move the world out of /zfs/ and seperate out module build tree
[zfs.git] / module / zcommon / zfs_namecheck.c
diff --git a/module/zcommon/zfs_namecheck.c b/module/zcommon/zfs_namecheck.c
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+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident  "%Z%%M% %I%     %E% SMI"
+
+/*
+ * Common name validation routines for ZFS.  These routines are shared by the
+ * userland code as well as the ioctl() layer to ensure that we don't
+ * inadvertently expose a hole through direct ioctl()s that never gets tested.
+ * In userland, however, we want significantly more information about _why_ the
+ * name is invalid.  In the kernel, we only care whether it's valid or not.
+ * Each routine therefore takes a 'namecheck_err_t' which describes exactly why
+ * the name failed to validate.
+ *
+ * Each function returns 0 on success, -1 on error.
+ */
+
+#if defined(_KERNEL)
+#include <sys/systm.h>
+#else
+#include <string.h>
+#endif
+
+#include <sys/param.h>
+#include <sys/nvpair.h>
+#include "zfs_namecheck.h"
+#include "zfs_deleg.h"
+
+static int
+valid_char(char c)
+{
+       return ((c >= 'a' && c <= 'z') ||
+           (c >= 'A' && c <= 'Z') ||
+           (c >= '0' && c <= '9') ||
+           c == '-' || c == '_' || c == '.' || c == ':' || c == ' ');
+}
+
+/*
+ * Snapshot names must be made up of alphanumeric characters plus the following
+ * characters:
+ *
+ *     [-_.:]
+ */
+int
+snapshot_namecheck(const char *path, namecheck_err_t *why, char *what)
+{
+       const char *loc;
+
+       if (strlen(path) >= MAXNAMELEN) {
+               if (why)
+                       *why = NAME_ERR_TOOLONG;
+               return (-1);
+       }
+
+       if (path[0] == '\0') {
+               if (why)
+                       *why = NAME_ERR_EMPTY_COMPONENT;
+               return (-1);
+       }
+
+       for (loc = path; *loc; loc++) {
+               if (!valid_char(*loc)) {
+                       if (why) {
+                               *why = NAME_ERR_INVALCHAR;
+                               *what = *loc;
+                       }
+                       return (-1);
+               }
+       }
+       return (0);
+}
+
+
+/*
+ * Permissions set name must start with the letter '@' followed by the
+ * same character restrictions as snapshot names, except that the name
+ * cannot exceed 64 characters.
+ */
+int
+permset_namecheck(const char *path, namecheck_err_t *why, char *what)
+{
+       if (strlen(path) >= ZFS_PERMSET_MAXLEN) {
+               if (why)
+                       *why = NAME_ERR_TOOLONG;
+               return (-1);
+       }
+
+       if (path[0] != '@') {
+               if (why) {
+                       *why = NAME_ERR_NO_AT;
+                       *what = path[0];
+               }
+               return (-1);
+       }
+
+       return (snapshot_namecheck(&path[1], why, what));
+}
+
+/*
+ * Dataset names must be of the following form:
+ *
+ *     [component][/]*[component][@component]
+ *
+ * Where each component is made up of alphanumeric characters plus the following
+ * characters:
+ *
+ *     [-_.:%]
+ *
+ * We allow '%' here as we use that character internally to create unique
+ * names for temporary clones (for online recv).
+ */
+int
+dataset_namecheck(const char *path, namecheck_err_t *why, char *what)
+{
+       const char *loc, *end;
+       int found_snapshot;
+
+       /*
+        * Make sure the name is not too long.
+        *
+        * ZFS_MAXNAMELEN is the maximum dataset length used in the userland
+        * which is the same as MAXNAMELEN used in the kernel.
+        * If ZFS_MAXNAMELEN value is changed, make sure to cleanup all
+        * places using MAXNAMELEN.
+        */
+
+       if (strlen(path) >= MAXNAMELEN) {
+               if (why)
+                       *why = NAME_ERR_TOOLONG;
+               return (-1);
+       }
+
+       /* Explicitly check for a leading slash.  */
+       if (path[0] == '/') {
+               if (why)
+                       *why = NAME_ERR_LEADING_SLASH;
+               return (-1);
+       }
+
+       if (path[0] == '\0') {
+               if (why)
+                       *why = NAME_ERR_EMPTY_COMPONENT;
+               return (-1);
+       }
+
+       loc = path;
+       found_snapshot = 0;
+       for (;;) {
+               /* Find the end of this component */
+               end = loc;
+               while (*end != '/' && *end != '@' && *end != '\0')
+                       end++;
+
+               if (*end == '\0' && end[-1] == '/') {
+                       /* trailing slashes are not allowed */
+                       if (why)
+                               *why = NAME_ERR_TRAILING_SLASH;
+                       return (-1);
+               }
+
+               /* Zero-length components are not allowed */
+               if (loc == end) {
+                       if (why) {
+                               /*
+                                * Make sure this is really a zero-length
+                                * component and not a '@@'.
+                                */
+                               if (*end == '@' && found_snapshot) {
+                                       *why = NAME_ERR_MULTIPLE_AT;
+                               } else {
+                                       *why = NAME_ERR_EMPTY_COMPONENT;
+                               }
+                       }
+
+                       return (-1);
+               }
+
+               /* Validate the contents of this component */
+               while (loc != end) {
+                       if (!valid_char(*loc) && *loc != '%') {
+                               if (why) {
+                                       *why = NAME_ERR_INVALCHAR;
+                                       *what = *loc;
+                               }
+                               return (-1);
+                       }
+                       loc++;
+               }
+
+               /* If we've reached the end of the string, we're OK */
+               if (*end == '\0')
+                       return (0);
+
+               if (*end == '@') {
+                       /*
+                        * If we've found an @ symbol, indicate that we're in
+                        * the snapshot component, and report a second '@'
+                        * character as an error.
+                        */
+                       if (found_snapshot) {
+                               if (why)
+                                       *why = NAME_ERR_MULTIPLE_AT;
+                               return (-1);
+                       }
+
+                       found_snapshot = 1;
+               }
+
+               /*
+                * If there is a '/' in a snapshot name
+                * then report an error
+                */
+               if (*end == '/' && found_snapshot) {
+                       if (why)
+                               *why = NAME_ERR_TRAILING_SLASH;
+                       return (-1);
+               }
+
+               /* Update to the next component */
+               loc = end + 1;
+       }
+}
+
+
+/*
+ * mountpoint names must be of the following form:
+ *
+ *     /[component][/]*[component][/]
+ */
+int
+mountpoint_namecheck(const char *path, namecheck_err_t *why)
+{
+       const char *start, *end;
+
+       /*
+        * Make sure none of the mountpoint component names are too long.
+        * If a component name is too long then the mkdir of the mountpoint
+        * will fail but then the mountpoint property will be set to a value
+        * that can never be mounted.  Better to fail before setting the prop.
+        * Extra slashes are OK, they will be tossed by the mountpoint mkdir.
+        */
+
+       if (path == NULL || *path != '/') {
+               if (why)
+                       *why = NAME_ERR_LEADING_SLASH;
+               return (-1);
+       }
+
+       /* Skip leading slash  */
+       start = &path[1];
+       do {
+               end = start;
+               while (*end != '/' && *end != '\0')
+                       end++;
+
+               if (end - start >= MAXNAMELEN) {
+                       if (why)
+                               *why = NAME_ERR_TOOLONG;
+                       return (-1);
+               }
+               start = end + 1;
+
+       } while (*end != '\0');
+
+       return (0);
+}
+
+/*
+ * For pool names, we have the same set of valid characters as described in
+ * dataset names, with the additional restriction that the pool name must begin
+ * with a letter.  The pool names 'raidz' and 'mirror' are also reserved names
+ * that cannot be used.
+ */
+int
+pool_namecheck(const char *pool, namecheck_err_t *why, char *what)
+{
+       const char *c;
+
+       /*
+        * Make sure the name is not too long.
+        *
+        * ZPOOL_MAXNAMELEN is the maximum pool length used in the userland
+        * which is the same as MAXNAMELEN used in the kernel.
+        * If ZPOOL_MAXNAMELEN value is changed, make sure to cleanup all
+        * places using MAXNAMELEN.
+        */
+       if (strlen(pool) >= MAXNAMELEN) {
+               if (why)
+                       *why = NAME_ERR_TOOLONG;
+               return (-1);
+       }
+
+       c = pool;
+       while (*c != '\0') {
+               if (!valid_char(*c)) {
+                       if (why) {
+                               *why = NAME_ERR_INVALCHAR;
+                               *what = *c;
+                       }
+                       return (-1);
+               }
+               c++;
+       }
+
+       if (!(*pool >= 'a' && *pool <= 'z') &&
+           !(*pool >= 'A' && *pool <= 'Z')) {
+               if (why)
+                       *why = NAME_ERR_NOLETTER;
+               return (-1);
+       }
+
+       if (strcmp(pool, "mirror") == 0 || strcmp(pool, "raidz") == 0) {
+               if (why)
+                       *why = NAME_ERR_RESERVED;
+               return (-1);
+       }
+
+       if (pool[0] == 'c' && (pool[1] >= '0' && pool[1] <= '9')) {
+               if (why)
+                       *why = NAME_ERR_DISKLIKE;
+               return (-1);
+       }
+
+       return (0);
+}
+
+/*
+ * Check if the dataset name is private for internal usage.
+ * '$' is reserved for internal dataset names. e.g. "$MOS"
+ *
+ * Return 1 if the given name is used internally.
+ * Return 0 if it is not.
+ */
+int
+dataset_name_hidden(const char *name)
+{
+       if (strchr(name, '$') != NULL)
+               return (1);
+
+       return (0);
+}