/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  linux/include/linux/sunrpc/clnt.h
 *
 *  Declarations for the high-level RPC client interface
 *
 *  Copyright (C) 1995, 1996, Olaf Kirch <okir@monad.swb.de>
 */

#ifndef _LINUX_SUNRPC_CLNT_H
#define _LINUX_SUNRPC_CLNT_H

#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/refcount.h>

#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/xprt.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/timer.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <asm/signal.h>
#include <linux/path.h>
#include <net/ipv6.h>
#include <linux/sunrpc/xprtmultipath.h>

struct rpc_inode;
struct rpc_sysfs_client {
        struct kobject kobject;
        struct net *net;
        struct rpc_clnt *clnt;
        struct rpc_xprt_switch *xprt_switch;
};


/*
 * The high-level client handle
 */
struct rpc_clnt {
        refcount_t              cl_count;       /* Number of references */
        unsigned int            cl_clid;        /* client id */
        struct list_head        cl_clients;     /* Global list of clients */
        struct list_head        cl_tasks;       /* List of tasks */
        atomic_t                cl_pid;         /* task PID counter */
        spinlock_t              cl_lock;        /* spinlock */
        struct rpc_xprt __rcu * cl_xprt;        /* transport */
        const struct rpc_procinfo *cl_procinfo; /* procedure info */
        u32                     cl_prog,        /* RPC program number */
                                cl_vers,        /* RPC version number */
                                cl_maxproc;     /* max procedure number */

        struct rpc_auth *       cl_auth;        /* authenticator */
        struct rpc_stat *       cl_stats;       /* per-program statistics */
        struct rpc_iostats *    cl_metrics;     /* per-client statistics */

        unsigned int            cl_softrtry : 1,/* soft timeouts */
                                cl_softerr  : 1,/* Timeouts return errors */
                                cl_discrtry : 1,/* disconnect before retry */
                                cl_noretranstimeo: 1,/* No retransmit timeouts */
                                cl_autobind : 1,/* use getport() */
                                cl_chatty   : 1,/* be verbose */
                                cl_shutdown : 1,/* rpc immediate -EIO */
                                cl_netunreach_fatal : 1;
                                                /* Treat ENETUNREACH errors as fatal */
        struct xprtsec_parms    cl_xprtsec;     /* transport security policy */

        struct rpc_rtt *        cl_rtt;         /* RTO estimator data */
        const struct rpc_timeout *cl_timeout;   /* Timeout strategy */

        atomic_t                cl_swapper;     /* swapfile count */
        int                     cl_nodelen;     /* nodename length */
        char                    cl_nodename[UNX_MAXNODENAME+1];
        struct rpc_pipe_dir_head cl_pipedir_objects;
        struct rpc_clnt *       cl_parent;      /* Points to parent of clones */
        struct rpc_rtt          cl_rtt_default;
        struct rpc_timeout      cl_timeout_default;
        const struct rpc_program *cl_program;
        const char *            cl_principal;   /* use for machine cred */
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
        struct dentry           *cl_debugfs;    /* debugfs directory */
#endif
        struct rpc_sysfs_client *cl_sysfs;      /* sysfs directory */
        /* cl_work is only needed after cl_xpi is no longer used,
         * and that are of similar size
         */
        union {
                struct rpc_xprt_iter    cl_xpi;
                struct work_struct      cl_work;
        };
        const struct cred       *cl_cred;
        unsigned int            cl_max_connect; /* max number of transports not to the same IP */
        struct super_block *pipefs_sb;
        atomic_t                cl_task_count;
};

/*
 * General RPC program info
 */
#define RPC_MAXVERSION          4
struct rpc_program {
        const char *            name;           /* protocol name */
        u32                     number;         /* program number */
        unsigned int            nrvers;         /* number of versions */
        const struct rpc_version **     version;        /* version array */
        struct rpc_stat *       stats;          /* statistics */
        const char *            pipe_dir_name;  /* path to rpc_pipefs dir */
};

struct rpc_version {
        u32                     number;         /* version number */
        unsigned int            nrprocs;        /* number of procs */
        const struct rpc_procinfo *procs;       /* procedure array */
        unsigned int            *counts;        /* call counts */
};

/*
 * Procedure information
 */
struct rpc_procinfo {
        u32                     p_proc;         /* RPC procedure number */
        kxdreproc_t             p_encode;       /* XDR encode function */
        kxdrdproc_t             p_decode;       /* XDR decode function */
        unsigned int            p_arglen;       /* argument hdr length (u32) */
        unsigned int            p_replen;       /* reply hdr length (u32) */
        unsigned int            p_timer;        /* Which RTT timer to use */
        u32                     p_statidx;      /* Which procedure to account */
        const char *            p_name;         /* name of procedure */
};

struct rpc_create_args {
        struct net              *net;
        int                     protocol;
        struct sockaddr         *address;
        size_t                  addrsize;
        struct sockaddr         *saddress;
        const struct rpc_timeout *timeout;
        const char              *servername;
        const char              *nodename;
        const struct rpc_program *program;
        struct rpc_stat         *stats;
        u32                     prognumber;     /* overrides program->number */
        u32                     version;
        rpc_authflavor_t        authflavor;
        u32                     nconnect;
        unsigned long           flags;
        char                    *client_name;
        struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
        const struct cred       *cred;
        unsigned int            max_connect;
        struct xprtsec_parms    xprtsec;
        unsigned long           connect_timeout;
        unsigned long           reconnect_timeout;
};

struct rpc_add_xprt_test {
        void (*add_xprt_test)(struct rpc_clnt *clnt,
                struct rpc_xprt *xprt,
                void *calldata);
        void *data;
};

/* Values for "flags" field */
#define RPC_CLNT_CREATE_HARDRTRY        (1UL << 0)
#define RPC_CLNT_CREATE_AUTOBIND        (1UL << 2)
#define RPC_CLNT_CREATE_NONPRIVPORT     (1UL << 3)
#define RPC_CLNT_CREATE_NOPING          (1UL << 4)
#define RPC_CLNT_CREATE_DISCRTRY        (1UL << 5)
#define RPC_CLNT_CREATE_QUIET           (1UL << 6)
#define RPC_CLNT_CREATE_INFINITE_SLOTS  (1UL << 7)
#define RPC_CLNT_CREATE_NO_IDLE_TIMEOUT (1UL << 8)
#define RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT      (1UL << 9)
#define RPC_CLNT_CREATE_SOFTERR         (1UL << 10)
#define RPC_CLNT_CREATE_REUSEPORT       (1UL << 11)
#define RPC_CLNT_CREATE_CONNECTED       (1UL << 12)
#define RPC_CLNT_CREATE_NETUNREACH_FATAL        (1UL << 13)

struct rpc_clnt *rpc_create(struct rpc_create_args *args);
struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *,
                                const struct rpc_program *, u32);
struct rpc_clnt *rpc_clone_client(struct rpc_clnt *);
struct rpc_clnt *rpc_clone_client_set_auth(struct rpc_clnt *,
                                rpc_authflavor_t);
int             rpc_switch_client_transport(struct rpc_clnt *,
                                struct xprt_create *,
                                const struct rpc_timeout *);

void            rpc_shutdown_client(struct rpc_clnt *);
void            rpc_release_client(struct rpc_clnt *);
void            rpc_task_release_transport(struct rpc_task *);
void            rpc_task_release_client(struct rpc_task *);
struct rpc_xprt *rpc_task_get_xprt(struct rpc_clnt *clnt,
                struct rpc_xprt *xprt);

int             rpcb_create_local(struct net *);
void            rpcb_put_local(struct net *);
int             rpcb_register(struct net *, u32, u32, int, unsigned short);
int             rpcb_v4_register(struct net *net, const u32 program,
                                 const u32 version,
                                 const struct sockaddr *address,
                                 const char *netid);
void            rpcb_getport_async(struct rpc_task *);

void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
                             unsigned int base, unsigned int len,
                             unsigned int hdrsize);
void            rpc_call_start(struct rpc_task *);
int             rpc_call_async(struct rpc_clnt *clnt,
                               const struct rpc_message *msg, int flags,
                               const struct rpc_call_ops *tk_ops,
                               void *calldata);
int             rpc_call_sync(struct rpc_clnt *clnt,
                              const struct rpc_message *msg, int flags);
struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred,
                               int flags);
int             rpc_restart_call_prepare(struct rpc_task *);
int             rpc_restart_call(struct rpc_task *);
void            rpc_setbufsize(struct rpc_clnt *, unsigned int, unsigned int);
struct net *    rpc_net_ns(struct rpc_clnt *);
size_t          rpc_max_payload(struct rpc_clnt *);
size_t          rpc_max_bc_payload(struct rpc_clnt *);
unsigned int    rpc_num_bc_slots(struct rpc_clnt *);
void            rpc_force_rebind(struct rpc_clnt *);
size_t          rpc_peeraddr(struct rpc_clnt *, struct sockaddr *, size_t);
const char      *rpc_peeraddr2str(struct rpc_clnt *, enum rpc_display_format_t);
int             rpc_localaddr(struct rpc_clnt *, struct sockaddr *, size_t);

int             rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
                        int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
                        void *data);

int             rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
                        struct rpc_xprt_switch *xps,
                        struct rpc_xprt *xprt,
                        void *dummy);
int             rpc_clnt_add_xprt(struct rpc_clnt *, struct xprt_create *,
                        int (*setup)(struct rpc_clnt *,
                                struct rpc_xprt_switch *,
                                struct rpc_xprt *,
                                void *),
                        void *data);
void            rpc_set_connect_timeout(struct rpc_clnt *clnt,
                        unsigned long connect_timeout,
                        unsigned long reconnect_timeout);

int             rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *,
                        struct rpc_xprt_switch *,
                        struct rpc_xprt *,
                        void *);
void            rpc_clnt_manage_trunked_xprts(struct rpc_clnt *);
void            rpc_clnt_probe_trunked_xprts(struct rpc_clnt *,
                        struct rpc_add_xprt_test *);

const char *rpc_proc_name(const struct rpc_task *task);

void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *, struct rpc_xprt *);
void rpc_clnt_xprt_switch_remove_xprt(struct rpc_clnt *, struct rpc_xprt *);
bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
                        const struct sockaddr *sap);
void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt);
void rpc_clnt_disconnect(struct rpc_clnt *clnt);
void rpc_cleanup_clids(void);

static inline int rpc_reply_expected(struct rpc_task *task)
{
        return (task->tk_msg.rpc_proc != NULL) &&
                (task->tk_msg.rpc_proc->p_decode != NULL);
}

static inline void rpc_task_close_connection(struct rpc_task *task)
{
        if (task->tk_xprt)
                xprt_force_disconnect(task->tk_xprt);
}
#endif /* _LINUX_SUNRPC_CLNT_H */