+/*
+ * Determine the mount path as a string
+ */
+static char *nfs4_path(const struct vfsmount *mnt_parent,
+ const struct dentry *dentry,
+ char *buffer, ssize_t buflen)
+{
+ const char *srvpath;
+
+ srvpath = strchr(mnt_parent->mnt_devname, ':');
+ if (srvpath)
+ srvpath++;
+ else
+ srvpath = mnt_parent->mnt_devname;
+
+ return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen);
+}
+
+/*
+ * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
+ * believe to be the server path to this dentry
+ */
+static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
+ const struct dentry *dentry,
+ const struct nfs4_fs_locations *locations,
+ char *page, char *page2)
+{
+ const char *path, *fs_path;
+
+ path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+
+ fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
+ if (IS_ERR(fs_path))
+ return PTR_ERR(fs_path);
+
+ if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
+ dprintk("%s: path %s does not begin with fsroot %s\n",
+ __FUNCTION__, path, fs_path);
+ return -ENOENT;
+ }
+
+ return 0;
+}
+
+/*
+ * Check if the string represents a "valid" IPv4 address
+ */
+static inline int valid_ipaddr4(const char *buf)
+{
+ int rc, count, in[4];
+
+ rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
+ if (rc != 4)
+ return -EINVAL;
+ for (count = 0; count < 4; count++) {
+ if (in[count] > 255)
+ return -EINVAL;
+ }
+ return 0;
+}