/* SPDX-License-Identifier: GPL-2.0 */ /* * linux/include/linux/sunrpc/svc.h * * RPC server declarations. * * Copyright (C) 1995, 1996 Olaf Kirch */ #ifndef SUNRPC_SVC_H #define SUNRPC_SVC_H #include #include #include #include #include #include #include #include #include #include /* * * 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 */ struct lwq sp_xprts; /* pending transports */ atomic_t sp_nrthreads; /* # of threads in pool */ struct list_head sp_all_threads; /* all server threads */ struct llist_head sp_idle_threads; /* idle server threads */ /* statistics on pool operation */ struct percpu_counter sp_messages_arrived; struct percpu_counter sp_sockets_queued; struct percpu_counter sp_threads_woken; unsigned long sp_flags; } ____cacheline_aligned_in_smp; /* bits for sp_flags */ enum { SP_TASK_PENDING, /* still work to do even if no xprt is queued */ SP_NEED_VICTIM, /* One thread needs to agree to exit */ SP_VICTIM_REMAINS, /* One thread needs to actually exit */ }; /* * 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; 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 lwq sv_cb_list; /* queue for callback requests * that arrive over the same * connection */ bool sv_bc_enabled; /* service uses backchannel */ #endif /* CONFIG_SUNRPC_BACKCHANNEL */ }; /* This is used by pool_stats to find and lock an svc */ struct svc_info { struct svc_serv *serv; struct mutex *mutex; }; void svc_destroy(struct svc_serv **svcp); /* * 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 Requests 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 ->sendmsg with MSG_SPLICE_PAGES 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) /* * The context of a single thread, including the request currently being * processed. */ struct svc_rqst { struct list_head rq_all; /* all threads list */ struct llist_node rq_idle; /* On the idle 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 folio_batch rq_fbatch; 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 */ unsigned long rq_flags; /* flags field */ ktime_t rq_qtime; /* enqueue time */ void * rq_argp; /* decoded arguments */ void * rq_resp; /* xdr'd results */ __be32 *rq_accept_statp; 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 task_struct *rq_task; /* service thread */ struct net *rq_bc_net; /* pointer to backchannel's * net namespace */ unsigned long bc_to_initval; unsigned int bc_to_retries; void ** rq_lease_breaker; /* The v4 client breaking a lease */ unsigned int rq_status_counter; /* RPC processing counter */ }; /* bits for rq_flags */ enum { RQ_SECURE, /* secure port */ RQ_LOCAL, /* local request */ RQ_USEDEFERRAL, /* use deferral */ RQ_DROPME, /* drop current reply */ RQ_VICTIM, /* Have agreed to shut down */ RQ_DATA, /* request has data */ }; #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; } /** * svc_thread_should_stop - check if this thread should stop * @rqstp: the thread that might need to stop * * To stop an svc thread, the pool flags SP_NEED_VICTIM and SP_VICTIM_REMAINS * are set. The first thread which sees SP_NEED_VICTIM clears it, becoming * the victim using this function. It should then promptly call * svc_exit_thread() to complete the process, clearing SP_VICTIM_REMAINS * so the task waiting for a thread to exit can wake and continue. * * Return values: * %true: caller should invoke svc_exit_thread() * %false: caller should do nothing */ static inline bool svc_thread_should_stop(struct svc_rqst *rqstp) { if (test_and_clear_bit(SP_NEED_VICTIM, &rqstp->rq_pool->sp_flags)) set_bit(RQ_VICTIM, &rqstp->rq_flags); return test_bit(RQ_VICTIM, &rqstp->rq_flags); } 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 *rqstp); 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 */ enum svc_auth_status (*pg_authenticate)(struct svc_rqst *rqstp); __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 long __percpu *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; /* Dispatch function */ int (*vs_dispatch)(struct svc_rqst *rqstp); }; /* * 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); bool svc_rqst_replace_page(struct svc_rqst *rqstp, struct page *page); void svc_rqst_release_pages(struct svc_rqst *rqstp); 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_info *si, struct file *file); void svc_process(struct svc_rqst *rqstp); void svc_process_bc(struct rpc_rqst *req, struct svc_rqst *rqstp); 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); void svc_pool_wake_idle_thread(struct svc_pool *pool); struct svc_pool *svc_pool_for_cpu(struct svc_serv *serv); 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 * */ 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; WARN_ON(buf->len != buf->head->iov_len + buf->page_len + buf->tail->iov_len); 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; buf->len = resv->iov_len; xdr->page_ptr = buf->pages - 1; buf->buflen = PAGE_SIZE * (rqstp->rq_page_end - buf->pages); xdr->rqst = NULL; } /** * svcxdr_encode_opaque_pages - Insert pages into an xdr_stream * @xdr: xdr_stream to be updated * @pages: array of pages to insert * @base: starting offset of first data byte in @pages * @len: number of data bytes in @pages to insert * * After the @pages are added, the tail iovec is instantiated pointing * to end of the head buffer, and the stream is set up to encode * subsequent items into the tail. */ static inline void svcxdr_encode_opaque_pages(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct page **pages, unsigned int base, unsigned int len) { xdr_write_pages(xdr, pages, base, len); xdr->page_ptr = rqstp->rq_next_page - 1; } /** * svcxdr_set_auth_slack - * @rqstp: RPC transaction * @slack: buffer space to reserve for the transaction's security flavor * * Set the request's slack space requirement, and set aside that much * space in the rqstp's rq_res.head for use when the auth wraps the Reply. */ static inline void svcxdr_set_auth_slack(struct svc_rqst *rqstp, int slack) { struct xdr_stream *xdr = &rqstp->rq_res_stream; struct xdr_buf *buf = &rqstp->rq_res; struct kvec *resv = buf->head; rqstp->rq_auth_slack = slack; xdr->end -= XDR_QUADLEN(slack); buf->buflen -= rqstp->rq_auth_slack; WARN_ON(xdr->iov != resv); WARN_ON(xdr->p > xdr->end); } /** * svcxdr_set_accept_stat - Reserve space for the accept_stat field * @rqstp: RPC transaction context * * Return values: * %true: Success * %false: No response buffer space was available */ static inline bool svcxdr_set_accept_stat(struct svc_rqst *rqstp) { struct xdr_stream *xdr = &rqstp->rq_res_stream; rqstp->rq_accept_statp = xdr_reserve_space(xdr, XDR_UNIT); if (unlikely(!rqstp->rq_accept_statp)) return false; *rqstp->rq_accept_statp = rpc_success; return true; } #endif /* SUNRPC_SVC_H */