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/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

extern struct svc_program	nfsd_program;
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.
 *
 * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a
 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0 (unless
 * nn->keep_active is set).  That number of nfsd threads must
 * exist and each must be listed in ->sp_all_threads in some entry of
 * ->sv_pools[].
 *
 * Each active thread holds a counted reference on nn->nfsd_serv, as does
 * the nn->keep_active flag and various transient calls to svc_get().
 *
 * 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 defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static struct svc_stat	nfsd_acl_svcstats;
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)

static struct svc_program	nfsd_acl_program = {
	.pg_prog		= NFS_ACL_PROGRAM,
	.pg_nvers		= NFSD_ACL_NRVERS,
	.pg_vers		= nfsd_acl_version,
	.pg_name		= "nfsacl",
	.pg_class		= "nfsd",
	.pg_stats		= &nfsd_acl_svcstats,
	.pg_authenticate	= &svc_set_client,
	.pg_init_request	= nfsd_acl_init_request,
	.pg_rpcbind_set		= nfsd_acl_rpcbind_set,
};

static struct svc_stat	nfsd_acl_svcstats = {
	.program	= &nfsd_acl_program,
};
#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */

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

#define NFSD_MINVERS    	2
#define NFSD_NRVERS		ARRAY_SIZE(nfsd_version)

struct svc_program		nfsd_program = {
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
	.pg_next		= &nfsd_acl_program,
#endif
	.pg_prog		= NFS_PROGRAM,		/* program number */
	.pg_nvers		= NFSD_NRVERS,		/* nr of entries in nfsd_version */
	.pg_vers		= nfsd_version,		/* version table */
	.pg_name		= "nfsd",		/* program name */
	.pg_class		= "nfsd",		/* authentication class */
	.pg_stats		= &nfsd_svcstats,	/* version table */
	.pg_authenticate	= &svc_set_client,	/* export authentication */
	.pg_init_request	= nfsd_init_request,
	.pg_rpcbind_set		= nfsd_rpcbind_set,
};

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

static bool *
nfsd_alloc_versions(void)
{
	bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL);
	unsigned i;

	if (vers) {
		/* All compiled versions are enabled by default */
		for (i = 0; i < NFSD_NRVERS; i++)
			vers[i] = nfsd_support_version(i);
	}
	return vers;
}

static bool *
nfsd_alloc_minorversions(void)
{
	bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION