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/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/include/linux/sunrpc/svc.h
*
* RPC server declarations.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef SUNRPC_SVC_H
#define SUNRPC_SVC_H
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/wait.h>
#include <linux/mm.h>
#include <linux/pagevec.h>
/* statistics for svc_pool structures */
struct svc_pool_stats {
atomic_long_t packets;
unsigned long sockets_queued;
atomic_long_t threads_woken;
atomic_long_t threads_timedout;
};
/*
*
* RPC service thread pool.
*
* Pool of threads and temporary sockets. Generally there is only
* a single one of these per RPC service, but on NUMA machines those
* services that can benefit from it (i.e. nfs but not lockd) will
* have one pool per NUMA node. This optimisation reduces cross-
* node traffic on multi-node NUMA NFS servers.
*/
struct svc_pool {
unsigned int sp_id; /* pool id; also node id on NUMA */
spinlock_t sp_lock; /* protects all fields */
struct list_head sp_sockets; /* pending sockets */
unsigned int sp_nrthreads; /* # of threads in pool */
struct list_head sp_all_threads; /* all server threads */
struct svc_pool_stats sp_stats; /* statistics on pool operation */
#define SP_TASK_PENDING (0) /* still work to do even if no
* xprt is queued. */
#define SP_CONGESTED (1)
unsigned long sp_flags;
} ____cacheline_aligned_in_smp;
/*
* RPC service.
*
* An RPC service is a ``daemon,'' possibly multithreaded, which
* receives and processes incoming RPC messages.
* It has one or more transport sockets associated with it, and maintains
* a list of idle threads waiting for input.
*
* We currently do not support more than one RPC program per daemon.
*/
struct svc_serv {
struct svc_program * sv_program; /* RPC program */
struct svc_stat * sv_stats; /* RPC statistics */
spinlock_t sv_lock;
struct kref sv_refcnt;
unsigned int sv_nrthreads; /* # of server threads */
unsigned int sv_maxconn; /* max connections allowed or
* '0' causing max to be based
* on number of threads. */
unsigned int sv_max_payload; /* datagram payload size */
unsigned int sv_max_mesg; /* max_payload + 1 page for overheads */
unsigned int sv_xdrsize; /* XDR buffer size */
struct list_head sv_permsocks; /* all permanent sockets */
struct list_head sv_tempsocks; /* all temporary sockets */
int sv_tmpcnt; /* count of temporary sockets */
struct timer_list sv_temptimer; /* timer for aging temporary sockets */
char * sv_name; /* service name */
unsigned int sv_nrpools; /* number of thread pools */
struct svc_pool * sv_pools; /* array of thread pools */
int (*sv_threadfn)(void *data);
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
struct list_head sv_cb_list; /* queue for callback requests
* that arrive over the same
* connection */
spinlock_t sv_cb_lock; /* protects the svc_cb_list */
wait_queue_head_t sv_cb_waitq; /* sleep here if there are no
* entries in the svc_cb_list */
bool sv_bc_enabled; /* service uses backchannel */
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
};
/**
* svc_get() - increment reference count on a SUNRPC serv
* @serv: the svc_serv to have count incremented
*
* Returns: the svc_serv that was passed in.
*/
static inline struct svc_serv *svc_get(struct svc_serv *serv)
{
kref_get(&serv->sv_refcnt);
return serv;
}
void svc_destroy(struct kref *);
/**
* svc_put - decrement reference count on a SUNRPC serv
* @serv: the svc_serv to have count decremented
*
* When the reference count reaches zero, svc_destroy()
* is called to clean up and free the serv.
*/
static inline void svc_put(struct svc_serv *serv)
{
kref_put(&serv->sv_refcnt, svc_destroy);
}
/*
* Maximum payload size supported by a kernel RPC server.
* This is use to determine the max number of pages nfsd is
* willing to return in a single READ operation.
*
* These happen to all be powers of 2, which is not strictly
* necessary but helps enforce the real limitation, which is
* that they should be multiples of PAGE_SIZE.
*
* For UDP transports, a block plus NFS,RPC, and UDP headers
* has to fit into the IP datagram limit of 64K. The largest
* feasible number for all known page sizes is probably 48K,
* but we choose 32K here. This is the same as the historical
* Linux limit; someone who cares more about NFS/UDP performance
* can test a larger number.
*
* For TCP transports we have more freedom. A size of 1MB is
* chosen to match the client limit. Other OSes are known to
* have larger limits, but those numbers are probably beyond
* the point of diminishing returns.
*/
#define RPCSVC_MAXPAYLOAD (1*1024*1024u)
#define RPCSVC_MAXPAYLOAD_TCP RPCSVC_MAXPAYLOAD
#define RPCSVC_MAXPAYLOAD_UDP (32*1024u)
extern u32 svc_max_payload(const struct svc_rqst *rqstp);
/*
* RPC Requsts and replies are stored in one or more pages.
* We maintain an array of pages for each server thread.
* Requests are copied into these pages as they arrive. Remaining
* pages are available to write the reply into.
*
* Pages are sent using ->sendpage so each server thread needs to
* allocate more to replace those used in sending. To help keep track
* of these pages we have a receive list where all pages initialy live,
* and a send list where pages are moved to when there are to be part
* of a reply.
*
* We use xdr_buf for holding responses as it fits well with NFS
* read responses (that have a header, and some data pages, and possibly
* a tail) and means we can share some client side routines.
*
* The xdr_buf.head kvec always points to the first page in the rq_*pages
* list. The xdr_buf.pages pointer points to the second page on that
* list. xdr_buf.tail points to the end of the first page.
* This assumes that the non-page part of an rpc reply will fit
* in a page - NFSd ensures this. lockd also has no trouble.
*
* Each request/reply pair can have at most one "payload", plus two pages,
* one for the request, and one for the reply.
* We using ->sendfile to return read data, we might need one extra page
* if the request is not page-aligned. So add another '1'.
*/
#define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \
+ 2 + 1)
static inline u32 svc_getnl(struct kvec *iov)
{
__be32 val, *vp;
vp = iov->iov_base;
val = *vp++;
iov->iov_base = (void*)vp;
iov->iov_len -= sizeof(__be32);
return ntohl(val);
}
static inline void svc_putnl(struct kvec *iov, u32 val)
{
__be32 *vp = iov->iov_base + iov->iov_len;
*vp = htonl(val);
iov->iov_len += sizeof(__be32);
}
static inline __be32 svc_getu32(struct kvec *iov)
{
__be32 val, *vp;
vp = iov->iov_base;
val = *vp++;
iov->iov_base = (void*)vp;
iov->iov_len -= sizeof(__be32);
return val;
}
static inline void svc_ungetu32(struct kvec *iov)
{
__be32 *vp = (__be32 *)iov->iov_base;
iov->iov_base = (void *)(vp - 1);
iov->iov_len += sizeof(*vp);
}
static inline void svc_putu32(struct kvec *iov, __be32 val)
{
__be32 *vp = iov->iov_base + iov->iov_len;
*vp = val;
iov->iov_len += sizeof(__be32);
}
/*
* The context of a single thread, including the request currently being
* processed.
*/
struct svc_rqst {
struct list_head rq_all; /* all threads list */
struct rcu_head rq_rcu_head; /* for RCU deferred kfree */
struct svc_xprt * rq_xprt; /* transport ptr */
struct sockaddr_storage rq_addr; /* peer address */
size_t rq_addrlen;
struct sockaddr_storage rq_daddr; /* dest addr of request
* - reply from here */
size_t rq_daddrlen;
struct svc_serv * rq_server; /* RPC service definition */
struct svc_pool * rq_pool; /* thread pool */
const struct svc_procedure *rq_procinfo;/* procedure info */
struct auth_ops * rq_authop; /* authentication flavour */
struct svc_cred rq_cred; /* auth info */
void * rq_xprt_ctxt; /* transport specific context ptr */
struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */
struct xdr_buf rq_arg;
struct xdr_stream rq_arg_stream;
struct xdr_stream rq_res_stream;
struct page *rq_scratch_page;
struct xdr_buf rq_res;
struct page *rq_pages[RPCSVC_MAXPAGES + 1];
struct page * *rq_respages; /* points into rq_pages */
struct page * *rq_next_page; /* next reply page to use */
struct page * *rq_page_end; /* one past the last page */
struct pagevec rq_pvec;
struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
struct bio_vec rq_bvec[RPCSVC_MAXPAGES];
__be32 rq_xid; /* transmission id */
u32 rq_prog; /* program number */
u32 rq_vers; /* program version */
u32 rq_proc; /* procedure number */
u32 rq_prot; /* IP protocol */
int rq_cachetype; /* catering to nfsd */
#define RQ_SECURE (0) /* secure port */
#define RQ_LOCAL (1) /* local request */
#define RQ_USEDEFERRAL (2) /* use deferral */
#define RQ_DROPME (3) /* drop current reply */
#define RQ_SPLICE_OK (4) /* turned off in gss privacy
* to prevent encrypting page
* cache pages */
#define RQ_VICTIM (5) /* about to be shut down */
#define RQ_BUSY (6) /* request is busy */
#define RQ_DATA (7) /* request has data */
unsigned long rq_flags; /* flags field */
ktime_t rq_qtime; /* enqueue time */
void * rq_argp; /* decoded arguments */
void * rq_resp; /* xdr'd results */
void * rq_auth_data; /* flavor-specific data */
__be32 rq_auth_stat; /* authentication status */
int rq_auth_slack; /* extra space xdr code
* should leave in head
* for krb5i, krb5p.
*/
int rq_reserved; /* space on socket outq
* reserved for this request
*/
ktime_t rq_stime; /* start time */
struct cache_req rq_chandle; /* handle passed to caches for
* request delaying
*/
/* Catering to nfsd */
struct auth_domain * rq_client; /* RPC peer info */
struct auth_domain * rq_gssclient; /* "gss/"-style peer info */
struct svc_cacherep * rq_cacherep; /* cache info */
struct task_struct *rq_task; /* service thread */
spinlock_t rq_lock; /* per-request lock */
struct net *rq_bc_net; /* pointer to backchannel's
* net namespace
*/
void ** rq_lease_breaker; /* The v4 client breaking a lease */
};
#define SVC_NET(rqst) (rqst->rq_xprt ? rqst->rq_xprt->xpt_net : rqst->rq_bc_net)
/*
* Rigorous type checking on sockaddr type conversions
*/
static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst)
{
return (struct sockaddr_in *) &rqst->rq_addr;
}
static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst)
{
return (struct sockaddr_in6 *) &rqst->rq_addr;
}
static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst)
{
return (struct sockaddr *) &rqst->rq_addr;
}
static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst)
{
return (struct sockaddr_in *) &rqst->rq_daddr;
}
static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst)
{
return (struct sockaddr_in6 *) &rqst->rq_daddr;
}
static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst)
{
return (struct sockaddr *) &rqst->rq_daddr;
}
/*
* Check buffer bounds after decoding arguments
*/
static inline int
xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p)
{
char *cp = (char *)p;
struct kvec *vec = &rqstp->rq_arg.head[0];
return cp >= (char*)vec->iov_base
&& cp <= (char*)vec->iov_base + vec->iov_len;
}
static inline int
xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p)
{
struct kvec *vec = &rqstp->rq_res.head[0];
char *cp = (char*)p;
vec->iov_len = cp - (char*)vec->iov_base;
return vec->iov_len <= PAGE_SIZE;
}
static inline void svc_free_res_pages(struct svc_rqst *rqstp)
{
while (rqstp->rq_next_page != rqstp->rq_respages) {
struct page **pp = --rqstp->rq_next_page;
if (*pp) {
put_page(*pp);
*pp = NULL;
}
}
}
struct svc_deferred_req {
u32 prot; /* protocol (UDP or TCP) */
struct svc_xprt *xprt;
struct sockaddr_storage addr; /* where reply must go */
size_t addrlen;
struct sockaddr_storage daddr; /* where reply must come from */
size_t daddrlen;
void *xprt_ctxt;
struct cache_deferred_req handle;
int argslen;
__be32 args[];
};
struct svc_process_info {
union {
int (*dispatch)(struct svc_rqst *, __be32 *);
struct {
unsigned int lovers;
unsigned int hivers;
} mismatch;
};
};
/*
* List of RPC programs on the same transport endpoint
*/
struct svc_program {
struct svc_program * pg_next; /* other programs (same xprt) */
u32 pg_prog; /* program number */
unsigned int pg_lovers; /* lowest version */
unsigned int pg_hivers; /* highest version */
unsigned int pg_nvers; /* number of versions */
const struct svc_version **pg_vers; /* version array */
char * pg_name; /* service name */
char * pg_class; /* class name: services sharing authentication */
int (*pg_authenticate)(struct svc_rqst *);
__be32 (*pg_init_request)(struct svc_rqst *,
const struct svc_program *,
struct svc_process_info *);
int (*pg_rpcbind_set)(struct net *net,
const struct svc_program *,
u32 version, int family,
unsigned short proto,
unsigned short port);
};
/*
* RPC program version
*/
struct svc_version {
u32 vs_vers; /* version number */
u32 vs_nproc; /* number of procedures */
const struct svc_procedure *vs_proc; /* per-procedure info */
unsigned int *vs_count; /* call counts */
u32 vs_xdrsize; /* xdrsize needed for this version */
/* Don't register with rpcbind */
bool vs_hidden;
/* Don't care if the rpcbind registration fails */
bool vs_rpcb_optnl;
/* Need xprt with congestion control */
bool vs_need_cong_ctrl;
/* Override dispatch function (e.g. when caching replies).
* A return value of 0 means drop the request.
* vs_dispatch == NULL means use default dispatcher.
*/
int (*vs_dispatch)(struct svc_rqst *, __be32 *);
};
/*
* RPC procedure info
*/
struct svc_procedure {
/* process the request: */
__be32 (*pc_func)(struct svc_rqst *);
/* XDR decode args: */
bool (*pc_decode)(struct svc_rqst *rqstp,
struct xdr_stream *xdr);
/* XDR encode result: */
bool (*pc_encode)(struct svc_rqst *rqstp,
struct xdr_stream *xdr);
/* XDR free result: */
void (*pc_release)(struct svc_rqst *);
unsigned int pc_argsize; /* argument struct size */
unsigned int pc_argzero; /* how much of argument to clear */
unsigned int pc_ressize; /* result struct size */
unsigned int pc_cachetype; /* cache info (NFS) */
unsigned int pc_xdrressize; /* maximum size of XDR reply */
const char * pc_name; /* for display */
};
/*
* Function prototypes.
*/
int svc_rpcb_setup(struct svc_serv *serv, struct net *net);
void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
int svc_bind(struct svc_serv *serv, struct net *net);
struct svc_serv *svc_create(struct svc_program *, unsigned int,
int (*threadfn)(void *data));
struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv,
struct svc_pool *pool, int node);
void svc_rqst_replace_page(struct svc_rqst *rqstp,
struct page *page);
void svc_rqst_free(struct svc_rqst *);
void svc_exit_thread(struct svc_rqst *);
struct svc_serv * svc_create_pooled(struct svc_program *prog,
struct svc_stat *stats,
unsigned int bufsize,
int (*threadfn)(void *data));
int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);
int svc_pool_stats_open(struct svc_serv *serv, struct file *file);
int svc_process(struct svc_rqst *);
int bc_svc_process(struct svc_serv *, struct rpc_rqst *,
struct svc_rqst *);
int svc_register(const struct svc_serv *, struct net *, const int,
const unsigned short, const unsigned short);
void svc_wake_up(struct svc_serv *);
void svc_reserve(struct svc_rqst *rqstp, int space);
struct svc_pool * svc_pool_for_cpu(struct svc_serv *serv, int cpu);
char * svc_print_addr(struct svc_rqst *, char *, size_t);
const char * svc_proc_name(const struct svc_rqst *rqstp);
int svc_encode_result_payload(struct svc_rqst *rqstp,
unsigned int offset,
unsigned int length);
unsigned int svc_fill_write_vector(struct svc_rqst *rqstp,
struct xdr_buf *payload);
char *svc_fill_symlink_pathname(struct svc_rqst *rqstp,
struct kvec *first, void *p,
size_t total);
__be32 svc_generic_init_request(struct svc_rqst *rqstp,
const struct svc_program *progp,
struct svc_process_info *procinfo);
int svc_generic_rpcbind_set(struct net *net,
const struct svc_program *progp,
u32 version, int family,
unsigned short proto,
unsigned short port);
int svc_rpcbind_set_version(struct net *net,
const struct svc_program *progp,
u32 version, int family,
unsigned short proto,
unsigned short port);
#define RPC_MAX_ADDRBUFLEN (63U)
/*
* When we want to reduce the size of the reserved space in the response
* buffer, we need to take into account the size of any checksum data that
* may be at the end of the packet. This is difficult to determine exactly
* for all cases without actually generating the checksum, so we just use a
* static value.
*/
static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space)
{
svc_reserve(rqstp, space + rqstp->rq_auth_slack);
}
/**
* svcxdr_init_decode - Prepare an xdr_stream for Call decoding
* @rqstp: controlling server RPC transaction context
*
* This function currently assumes the RPC header in rq_arg has
* already been decoded. Upon return, xdr->p points to the
* location of the upper layer header.
*/
static inline void svcxdr_init_decode(struct svc_rqst *rqstp)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct xdr_buf *buf = &rqstp->rq_arg;
struct kvec *argv = buf->head;
/*
* svc_getnl() and friends do not keep the xdr_buf's ::len
* field up to date. Refresh that field before initializing
* the argument decoding stream.
*/
buf->len = buf->head->iov_len + buf->page_len + buf->tail->iov_len;
xdr_init_decode(xdr, buf, argv->iov_base, NULL);
xdr_set_scratch_page(xdr, rqstp->rq_scratch_page);
}
/**
* svcxdr_init_encode - Prepare an xdr_stream for svc Reply encoding
* @rqstp: controlling server RPC transaction context
*
*/
static inline void svcxdr_init_encode(struct svc_rqst *rqstp)
{
struct xdr_stream *xdr = &rqstp->rq_res_stream;
struct xdr_buf *buf = &rqstp->rq_res;
struct kvec *resv = buf->head;
xdr_reset_scratch_buffer(xdr);
xdr->buf = buf;
xdr->iov = resv;
xdr->p = resv->iov_base + resv->iov_len;
xdr->end = resv->iov_base + PAGE_SIZE - rqstp->rq_auth_slack;
buf->len = resv->iov_len;
xdr->page_ptr = buf->pages - 1;
buf->buflen = PAGE_SIZE * (rqstp->rq_page_end - buf->pages);
buf->buflen -= rqstp->rq_auth_slack;
xdr->rqst = NULL;
}
#endif /* SUNRPC_SVC_H */
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