linux/fs/nfs/nfs4namespace.c

// SPDX-License-Identifier: GPL-2.0
/*
 * linux/fs/nfs/nfs4namespace.c
 *
 * Copyright (C) 2005 Trond Myklebust <[email protected]>
 * - Modified by David Howells <[email protected]>
 *
 * NFSv4 namespace
 */

#include <linux/module.h>
#include <linux/dcache.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/addr.h>
#include <linux/vfs.h>
#include <linux/inet.h>
#include "internal.h"
#include "nfs4_fs.h"
#include "nfs.h"
#include "dns_resolve.h"

#define NFSDBG_FACILITY …

/*
 * Work out the length that an NFSv4 path would render to as a standard posix
 * path, with a leading slash but no terminating slash.
 */
static ssize_t nfs4_pathname_len(const struct nfs4_pathname *pathname)
{ … }

/*
 * Convert the NFSv4 pathname components into a standard posix path.
 */
static char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
				  unsigned short *_len)
{ … }

/*
 * return the path component of "<server>:<path>"
 *  nfspath - the "<server>:<path>" string
 *  end - one past the last char that could contain "<server>:"
 * returns NULL on failure
 */
static char *nfs_path_component(const char *nfspath, const char *end)
{ … }

/*
 * Determine the mount path as a string
 */
static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t 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(struct dentry *dentry,
				const struct nfs4_fs_locations *locations,
				struct nfs_fs_context *ctx)
{ … }

size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr_storage *ss,
			     size_t salen, struct net *net, int port)
{ … }

/**
 * nfs_find_best_sec - Find a security mechanism supported locally
 * @clnt: pointer to rpc_clnt
 * @server: NFS server struct
 * @flavors: List of security tuples returned by SECINFO procedure
 *
 * Return an rpc client that uses the first security mechanism in
 * "flavors" that is locally supported.  The "flavors" array
 * is searched in the order returned from the server, per RFC 3530
 * recommendation and each flavor is checked for membership in the
 * sec= mount option list if it exists.
 *
 * Return -EPERM if no matching flavor is found in the array.
 *
 * Please call rpc_shutdown_client() when you are done with this rpc client.
 *
 */
static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt,
					  struct nfs_server *server,
					  struct nfs4_secinfo_flavors *flavors)
{ … }

/**
 * nfs4_negotiate_security - in response to an NFS4ERR_WRONGSEC on lookup,
 * return an rpc_clnt that uses the best available security flavor with
 * respect to the secinfo flavor list and the sec= mount options.
 *
 * @clnt: RPC client to clone
 * @inode: directory inode
 * @name: lookup name
 *
 * Please call rpc_shutdown_client() when you are done with this rpc client.
 */
struct rpc_clnt *
nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode,
					const struct qstr *name)
{ … }

static int try_location(struct fs_context *fc,
			const struct nfs4_fs_location *location)
{ … }

/**
 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
 * @fc: pointer to struct nfs_fs_context
 * @locations: array of NFSv4 server location information
 *
 */
static int nfs_follow_referral(struct fs_context *fc,
			       const struct nfs4_fs_locations *locations)
{ … }

/*
 * nfs_do_refmount - handle crossing a referral on server
 * @dentry - dentry of referral
 *
 */
static int nfs_do_refmount(struct fs_context *fc, struct rpc_clnt *client)
{ … }

int nfs4_submount(struct fs_context *fc, struct nfs_server *server)
{ … }

/*
 * Try one location from the fs_locations array.
 *
 * Returns zero on success, or a negative errno value.
 */
static int nfs4_try_replacing_one_location(struct nfs_server *server,
		char *page, char *page2,
		const struct nfs4_fs_location *location)
{ … }

/**
 * nfs4_replace_transport - set up transport to destination server
 *
 * @server: export being migrated
 * @locations: fs_locations array
 *
 * Returns zero on success, or a negative errno value.
 *
 * The client tries all the entries in the "locations" array, in the
 * order returned by the server, until one works or the end of the
 * array is reached.
 */
int nfs4_replace_transport(struct nfs_server *server,
			   const struct nfs4_fs_locations *locations)
{ … }