/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
 */
#ifndef NFSD_EXPORT_H
#define NFSD_EXPORT_H

#include <linux/sunrpc/cache.h>
#include <linux/percpu_counter.h>
#include <linux/workqueue.h>
#include <uapi/linux/nfsd/export.h>
#include <linux/nfs4.h>

struct knfsd_fh;
struct svc_fh;
struct svc_rqst;

/*
 * FS Locations
 */

#define MAX_FS_LOCATIONS        128

struct nfsd4_fs_location {
        char *hosts; /* colon separated list of hosts */
        char *path;  /* slash separated list of path components */
};

struct nfsd4_fs_locations {
        uint32_t locations_count;
        struct nfsd4_fs_location *locations;
/* If we're not actually serving this data ourselves (only providing a
 * list of replicas that do serve it) then we set "migrated": */
        int migrated;
};

/*
 * We keep an array of pseudoflavors with the export, in order from most
 * to least preferred.  For the foreseeable future, we don't expect more
 * than the eight pseudoflavors null, unix, krb5, krb5i, krb5p, skpm3,
 * spkm3i, and spkm3p (and using all 8 at once should be rare).
 */
#define MAX_SECINFO_LIST        8
#define EX_UUID_LEN             16

struct exp_flavor_info {
        u32     pseudoflavor;
        u32     flags;
};

/* Per-export stats */
enum {
        EXP_STATS_FH_STALE,
        EXP_STATS_IO_READ,
        EXP_STATS_IO_WRITE,
        EXP_STATS_COUNTERS_NUM
};

struct export_stats {
        time64_t                start_time;
        struct percpu_counter   counter[EXP_STATS_COUNTERS_NUM];
};

struct svc_export {
        struct cache_head       h;
        struct auth_domain *    ex_client;
        int                     ex_flags;
        int                     ex_fsid;
        struct path             ex_path;
        kuid_t                  ex_anon_uid;
        kgid_t                  ex_anon_gid;
        unsigned char *         ex_uuid; /* 16 byte fsid */
        struct nfsd4_fs_locations ex_fslocs;
        uint32_t                ex_nflavors;
        struct exp_flavor_info  ex_flavors[MAX_SECINFO_LIST];
        u32                     ex_layout_types;
        struct nfsd4_deviceid_map *ex_devid_map;
        struct cache_detail     *cd;
        struct rcu_work         ex_rwork;
        unsigned long           ex_xprtsec_modes;
        struct export_stats     *ex_stats;
};

/* an "export key" (expkey) maps a filehandlefragement to an
 * svc_export for a given client.  There can be several per export,
 * for the different fsid types.
 */
struct svc_expkey {
        struct cache_head       h;

        struct auth_domain *    ek_client;
        u8                      ek_fsidtype;
        u32                     ek_fsid[6];

        struct path             ek_path;
        struct rcu_work         ek_rwork;
};

#define EX_ISSYNC(exp)          (!((exp)->ex_flags & NFSEXP_ASYNC))
#define EX_NOHIDE(exp)          ((exp)->ex_flags & NFSEXP_NOHIDE)
#define EX_WGATHER(exp)         ((exp)->ex_flags & NFSEXP_GATHERED_WRITES)

struct svc_cred;
int nfsexp_flags(struct svc_cred *cred, struct svc_export *exp);
__be32 check_xprtsec_policy(struct svc_export *exp, struct svc_rqst *rqstp);
__be32 check_security_flavor(struct svc_export *exp, struct svc_rqst *rqstp,
                             bool may_bypass_gss);
__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
                         bool may_bypass_gss);

/*
 * Function declarations
 */
int                     nfsd_export_wq_init(void);
void                    nfsd_export_wq_shutdown(void);
int                     nfsd_export_init(struct net *);
void                    nfsd_export_shutdown(struct net *);
void                    nfsd_export_flush(struct net *);
struct svc_export *     rqst_exp_get_by_name(struct svc_rqst *,
                                             const struct path *);
struct svc_export *     rqst_exp_parent(struct svc_rqst *,
                                        struct path *);
struct svc_export *     rqst_find_fsidzero_export(struct svc_rqst *);
int                     exp_rootfh(struct net *, struct auth_domain *,
                                        char *path, struct knfsd_fh *, int maxsize);
__be32                  exp_pseudoroot(struct svc_rqst *, struct svc_fh *);

static inline void exp_put(struct svc_export *exp)
{
        cache_put(&exp->h, exp->cd);
}

static inline struct svc_export *exp_get(struct svc_export *exp)
{
        cache_get(&exp->h);
        return exp;
}
struct svc_export *rqst_exp_find(struct cache_req *reqp, struct net *net,
                                 struct auth_domain *cl, struct auth_domain *gsscl,
                                 int fsid_type, u32 *fsidv);

#endif /* NFSD_EXPORT_H */