path: root/fs/nfsd/nfssvc.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Central processing for nfsd.
 *
 * Authors:	Olaf Kirch (okir@monad.swb.de)
 *
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/sched/signal.h>
#include <linux/freezer.h>
#include <linux/module.h>
#include <linux/fs_struct.h>
#include <linux/swap.h>
#include <linux/siphash.h>

#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/svc_xprt.h>
#include <linux/lockd/bind.h>
#include <linux/nfsacl.h>
#include <linux/nfslocalio.h>
#include <linux/seq_file.h>
#include <linux/inetdevice.h>
#include <net/addrconf.h>
#include <net/ipv6.h>
#include <net/net_namespace.h>
#include "nfsd.h"
#include "cache.h"
#include "vfs.h"
#include "netns.h"
#include "filecache.h"

#include "trace.h"

#define NFSDDBG_FACILITY	NFSDDBG_SVC

atomic_t			nfsd_th_cnt = ATOMIC_INIT(0);
static int			nfsd(void *vrqstp);
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static int			nfsd_acl_rpcbind_set(struct net *,
						     const struct svc_program *,
						     u32, int,
						     unsigned short,
						     unsigned short);
static __be32			nfsd_acl_init_request(struct svc_rqst *,
						const struct svc_program *,
						struct svc_process_info *);
#endif
static int			nfsd_rpcbind_set(struct net *,
						 const struct svc_program *,
						 u32, int,
						 unsigned short,
						 unsigned short);
static __be32			nfsd_init_request(struct svc_rqst *,
						const struct svc_program *,
						struct svc_process_info *);

/*
 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and some members
 * of the svc_serv struct such as ->sv_temp_socks and ->sv_permsocks.
 *
 * Finally, the nfsd_mutex also protects some of the global variables that are
 * accessed when nfsd starts and that are settable via the write_* routines in
 * nfsctl.c. In particular:
 *
 *	user_recovery_dirname
 *	user_lease_time
 *	nfsd_versions
 */
DEFINE_MUTEX(nfsd_mutex);

/*
 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
 * nfsd_drc_max_pages limits the total amount of memory available for
 * version 4.1 DRC caches.
 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
 */
DEFINE_SPINLOCK(nfsd_drc_lock);
unsigned long	nfsd_drc_max_mem;
unsigned long	nfsd_drc_mem_used;

#if IS_ENABLED(CONFIG_NFS_LOCALIO)
static const struct svc_version *localio_versions[] = {
	[1] = &localio_version1,
};

#define NFSD_LOCALIO_NRVERS		ARRAY_SIZE(localio_versions)

#endif /* CONFIG_NFS_LOCALIO */

#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static const struct svc_version *nfsd_acl_version[] = {
# if defined(CONFIG_NFSD_V2_ACL)
	[2] = &nfsd_acl_version2,
# endif
# if defined(CONFIG_NFSD_V3_ACL)
	[3] = &nfsd_acl_version3,
# endif
};

#define NFSD_ACL_MINVERS	2
#define NFSD_ACL_NRVERS		ARRAY_SIZE(nfsd_acl_version)

#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */

static const struct svc_version *nfsd_version[NFSD_MAXVERS+1] = {
#if defined(CONFIG_NFSD_V2)
	[2] = &nfsd_version2,
#endif
	[3] = &nfsd_version3,
#if defined(CONFIG_NFSD_V4)
	[4] = &nfsd_version4,
#endif
};

struct svc_program		nfsd_programs[] = {
	{
	.pg_prog		= NFS_PROGRAM,		/* program number */
	.pg_nvers		= NFSD_MAXVERS+1,	/* nr of entries in nfsd_version */
	.pg_vers		= nfsd_version,		/* version table */
	.pg_name		= "nfsd",		/* program name */
	.pg_class		= "nfsd",		/* authentication class */
	.pg_authenticate	= svc_set_client,	/* export authentication */
	.pg_init_request	= nfsd_init_request,
	.pg_rpcbind_set		= nfsd_rpcbind_set,
	},
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
	{
	.pg_prog		= NFS_ACL_PROGRAM,
	.pg_nvers		= NFSD_ACL_NRVERS,
	.pg_vers		= nfsd_acl_version,
	.pg_name		= "nfsacl",
	.pg_class		= "nfsd",
	.pg_authenticate	= svc_set_client,
	.pg_init_request	= nfsd_acl_init_request,
	.pg_rpcbind_set		= nfsd_acl_rpcbind_set,
	},
#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
#if IS_ENABLED(CONFIG_NFS_LOCALIO)
	{
	.pg_prog		= NFS_LOCALIO_PROGRAM,
	.pg_nvers		= NFSD_LOCALIO_NRVERS,
	.pg_vers		= localio_versions,
	.pg_name		= "nfslocalio",
	.pg_class		= "nfsd",
	.pg_authenticate	= svc_set_client,
	.pg_init_request	= svc_generic_init_request,
	.pg_rpcbind_set		= svc_generic_rpcbind_set,
	}
#endif /* CONFIG_NFS_LOCALIO */
};

bool nfsd_support_version(int vers)
{
	if (vers >= NFSD_MINVERS && vers <= NFSD_MAXVERS)
		return nfsd_version[vers] != NULL;
	return false;
}

int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change)
{
	if (vers < NFSD_MINVERS || vers > NFSD_MAXVERS)
		return 0;
	switch(change) {
	case NFSD_SET:
		nn->nfsd_versions[vers] = nfsd_support_version(vers);
		break;
	case NFSD_CLEAR:
		nn->nfsd_versions[vers] = false;
		break;
	case NFSD_TEST:
		return nn->nfsd_versions[vers];
	case NFSD_AVAIL:
		return nfsd_support_version(vers);
	}
	return 0;
}

static void
nfsd_adjust_nfsd_versions4(struct nfsd_net *nn)
{
	unsigned i;

	for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
		if (nn->nfsd4_minorversions[i])
			return;
	}
	nfsd_vers(nn, 4