// SPDX-License-Identifier: GPL-2.0-only /* * linux/net/sunrpc/svc.c * * High-level RPC service routines * * Copyright (C) 1995, 1996 Olaf Kirch * * Multiple threads pools and NUMAisation * Copyright (c) 2006 Silicon Graphics, Inc. * by Greg Banks */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define RPCDBG_FACILITY RPCDBG_SVCDSP static void svc_unregister(const struct svc_serv *serv, struct net *net); #define svc_serv_is_pooled(serv) ((serv)->sv_ops->svo_function) #define SVC_POOL_DEFAULT SVC_POOL_GLOBAL /* * Structure for mapping cpus to pools and vice versa. * Setup once during sunrpc initialisation. */ struct svc_pool_map svc_pool_map = { .mode = SVC_POOL_DEFAULT }; EXPORT_SYMBOL_GPL(svc_pool_map); static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */ static int param_set_pool_mode(const char *val, const struct kernel_param *kp) { int *ip = (int *)kp->arg; struct svc_pool_map *m = &svc_pool_map; int err; mutex_lock(&svc_pool_map_mutex); err = -EBUSY; if (m->count) goto out; err = 0; if (!strncmp(val, "auto", 4)) *ip = SVC_POOL_AUTO; else if (!strncmp(val, "global", 6)) *ip = SVC_POOL_GLOBAL; else if (!strncmp(val, "percpu", 6)) *ip = SVC_POOL_PERCPU; else if (!strncmp(val, "pernode", 7)) *ip = SVC_POOL_PERNODE; else err = -EINVAL; out: mutex_unlock(&svc_pool_map_mutex); return err; } static int param_get_pool_mode(char *buf, const struct kernel_param *kp) { int *ip = (int *)kp->arg; switch (*ip) { case SVC_POOL_AUTO: return strlcpy(buf, "auto\n", 20); case SVC_POOL_GLOBAL: return strlcpy(buf, "global\n", 20); case SVC_POOL_PERCPU: return strlcpy(buf, "percpu\n", 20); case SVC_POOL_PERNODE: return strlcpy(buf, "pernode\n", 20); default: return sprintf(buf, "%d\n", *ip); } } module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode, &svc_pool_map.mode, 0644); /* * Detect best pool mapping mode heuristically, * according to the machine's topology. */ static int svc_pool_map_choose_mode(void) { unsigned int node; if (nr_online_nodes > 1) { /* * Actually have multiple NUMA nodes, * so split pools on NUMA node boundaries */ return SVC_POOL_PERNODE; } node = first_online_node; if (nr_cpus_node(node) > 2) { /* * Non-trivial SMP, or CONFIG_NUMA on * non-NUMA hardware, e.g. with a generic * x86_64 kernel on Xeons. In this case we * want to divide the pools on cpu boundaries. */ return SVC_POOL_PERCPU; } /* default: one global pool */ return SVC_POOL_GLOBAL; } /* * Allocate the to_pool[] and pool_to[] arrays. * Returns 0 on success or an errno. */ static int svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools) { m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL); if (!m->to_pool) goto fail; m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL); if (!m->pool_to) goto fail_free; return 0; fail_free: kfree(m->to_pool); m->to_pool = NULL; fail: return -ENOMEM; } /* * Initialise the pool map for SVC_POOL_PERCPU mode. * Returns number of pools or <0 on error. */ static int svc_pool_map_init_percpu(struct svc_pool_map *m) { unsigned int maxpools = nr_cpu_ids; unsigned int pidx = 0; unsigned int cpu; int err; err = svc_pool_map_alloc_arrays(m, maxpools); if (err) return err; for_each_online_cpu(cpu) { BUG_ON(pidx >= maxpools); m->to_pool[cpu] = pidx; m->pool_to[pidx] = cpu; pidx++; } /* cpus brought online later all get mapped to pool0, sorry */ return pidx; }; /* * Initialise the pool map for SVC_POOL_PERNODE mode. * Returns number of pools or <0 on error. */ static int svc_pool_map_init_pernode(struct svc_pool_map *m) { unsigned int maxpools = nr_node_ids; unsigned int pidx = 0; unsigned int node; int err; err = svc_pool_map_alloc_arrays(m, maxpools); if (err) return err; for_each_node_with_cpus(node) { /* some architectures (e.g. SN2) have cpuless nodes */ BUG_ON(pidx > maxpools); m->to_pool[node] = pidx; m->pool_to[pidx] = node; pidx++; } /* nodes brought online later all get mapped to pool0, sorry */ return pidx; } /* * Add a reference to the global map of cpus to pools (and * vice versa). Initialise the map if we're the first user. * Returns the number of pools. */ unsigned int svc_pool_map_get(void) { struct svc_pool_map *m = &svc_pool_map; int npools = -1; mutex_lock(&svc_pool_map_mutex); if (m->count++) { mutex_unlock(&svc_pool_map_mutex); return m->npools; } if (m->mode == SVC_POOL_AUTO) m->mode = svc_pool_map_choose_mode(); switch (m->mode) { case SVC_POOL_PERCPU: npools = svc_pool_map_init_percpu(m); break; case SVC_POOL_PERNODE: npools = svc_pool_map_init_pernode(m); break; } if (npools < 0) { /* default, or memory allocation failure */ npools = 1; m->mode = SVC_POOL_GLOBAL; } m->npools = npools; mutex_unlock(&svc_pool_map_mutex); return m->npools; } EXPORT_SYMBOL_GPL(svc_pool_map_get); /* * Drop a reference to the global map of cpus to pools. * When the last reference is dropped, the map data is * freed; this allows the sysadmin to change the pool * mode using the pool_mode module option without * rebooting or re-loading sunrpc.ko. */ void svc_pool_map_put(void) { struct svc_pool_map *m = &svc_pool_map; mutex_lock(&svc_pool_map_mutex); if (!--m->count) { kfree(m->to_pool); m->to_pool = NULL; kfree(m->pool_to); m->pool_to = NULL; m->npools = 0; } mutex_unlock(&svc_pool_map_mutex); } EXPORT_SYMBOL_GPL(svc_pool_map_put); static int svc_pool_map_get_node(unsigned int pidx) { const struct svc_pool_map *m = &svc_pool_map; if (m->count) { if (m->mode == SVC_POOL_PERCPU) return cpu_to_node(m->pool_to[pidx]); if (m->mode == SVC_POOL_PERNODE) return m->pool_to[pidx]; } return NUMA_NO_NODE; } /* * Set the given thread's cpus_allowed mask so that it * will only run on cpus in the given pool. */ static inline void svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx) { struct svc_pool_map *m = &svc_pool_map; unsigned int node = m->pool_to[pidx]; /* * The caller checks for sv_nrpools > 1, which * implies that we've been initialized. */ WARN_ON_ONCE(m->count == 0); if (m->count == 0) return; switch (m->mode) { case SVC_POOL_PERCPU: { set_cpus_allowed_ptr(task, cpumask_of(node)); break; } case SVC_POOL_PERNODE: { set_cpus_allowed_ptr(task, cpumask_of_node(node)); break; } } } /* * Use the mapping mode to choose a pool for a given CPU. * Used when enqueueing an incoming RPC. Always returns * a non-NULL pool pointer. */ struct svc_pool * svc_pool_for_cpu(struct svc_serv *serv, int cpu) { struct svc_pool_map *m = &svc_pool_map; unsigned int pidx = 0; /* * An uninitialised map happens in a pure client when * lockd is brought up, so silently treat it the * same as SVC_POOL_GLOBAL. */ if (svc_serv_is_pooled(serv)) { switch (m->mode) { case SVC_POOL_PERCPU: pidx = m->to_pool[cpu]; break; case SVC_POOL_PERNODE: pidx = m->to_pool[cpu_to_node(cpu)]; break; } } return &serv->sv_pools[pidx % serv->sv_nrpools]; } int svc_rpcb_setup(struct svc_serv *serv, struct net *net) { int err; err = rpcb_create_local(net); if (err) return err; /* Remove any stale portmap registrations */ svc_unregister(serv, net); return 0; } EXPORT_SYMBOL_GPL(svc_rpcb_setup); void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net) { svc_unregister(serv, net); rpcb_put_local(net); } EXPORT_SYMBOL_GPL(svc_rpcb_cleanup); static int svc_uses_rpcbind(struct svc_serv *serv) { struct svc_program *progp; unsigned int i; for (progp = serv->sv_program; progp; progp = progp->pg_next) { for (i = 0; i < progp->pg_nvers; i++) { if (progp->pg_vers[i] == NULL) continue; if (!progp->pg_vers[i]->vs_hidden) return 1; } } return 0; } int svc_bind(struct svc_serv *serv, struct net *net) { if (!svc_uses_rpcbind(serv)) return 0; return svc_rpcb_setup(serv, net); } EXPORT_SYMBOL_GPL(svc_bind); #if defined(CONFIG_SUNRPC_BACKCHANNEL) static void __svc_init_bc(struct svc_serv *serv) { INIT_LIST_HEAD(&serv->sv_cb_list); spin_lock_init(&serv->sv_cb_lock); init_waitqueue_head(&serv->sv_cb_waitq); } #else static void __svc_init_bc(struct svc_serv *serv) { } #endif /* * Create an RPC service */ static struct svc_serv * __svc_create(struct svc_program *prog, unsigned int bufsize, int npools, const struct svc_serv_ops *ops) { struct svc_serv *serv; unsigned int vers; unsigned int xdrsize; unsigned int i; if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL))) return NULL; serv->sv_name = prog->pg_name; serv->sv_program = prog; serv->sv_nrthreads = 1; serv->sv_stats = prog->pg_stats; if (bufsize > RPCSVC_MAXPAYLOAD) bufsize = RPCSVC_MAXPAYLOAD; serv->sv_max_payload = bufsize? bufsize : 4096; serv->sv_max_mesg = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE); serv->sv_ops = ops; xdrsize = 0; while (prog) { prog->pg_lovers = prog->pg_nvers-1; for (vers=0; verspg_nvers ; vers++) if (prog->pg_vers[vers]) { prog->pg_hivers = vers; if (prog->pg_lovers > vers) prog->pg_lovers = vers; if (prog->pg_vers[vers]->vs_xdrsize > xdrsize) xdrsize = prog->pg_vers[vers]->vs_xdrsize; } prog = prog->pg_next; } serv->sv_xdrsize = xdrsize; INIT_LIST_HEAD(&serv->sv_tempsocks); INIT_LIST_HEAD(&serv->sv_permsocks); timer_setup(&serv->sv_temptimer, NULL, 0); spin_lock_init(&serv->sv_lock); __svc_init_bc(serv); serv->sv_nrpools = npools; serv->sv_pools = kcalloc(serv->sv_nrpools, sizeof(struct svc_pool), GFP_KERNEL); if (!serv->sv_pools) { kfree(serv); return NULL; } for (i = 0; i < serv->sv_nrpools; i++) { struct svc_pool *pool = &serv->sv_pools[i]; dprintk("svc: initialising pool %u for %s\n", i, serv->sv_name); pool->sp_id = i; INIT_LIST_HEAD(&pool->sp_sockets); INIT_LIST_HEAD(&pool->sp_all_threads); spin_lock_init(&pool->sp_lock); } return serv; } struct svc_serv * svc_create(struct svc_program *prog, unsigned int bufsize, const struct svc_serv_ops *ops) { return __svc_create(prog, bufsize, /*npools*/1, ops); } EXPORT_SYMBOL_GPL(svc_create); struct svc_serv * svc_create_pooled(struct svc_program *prog, unsigned int bufsize, const struct svc_serv_ops *ops) { struct svc_serv *serv; unsigned int npools = svc_pool_map_get(); serv = __svc_create(prog, bufsize, npools, ops); if (!serv) goto out_err; return serv; out_err: svc_pool_map_put(); return NULL; } EXPORT_SYMBOL_GPL(svc_create_pooled); void svc_shutdown_net(struct svc_serv *serv, struct net *net) { svc_close_net(serv, net); if (serv->sv_ops->svo_shutdown) serv->sv_ops->svo_shutdown(serv, net); } EXPORT_SYMBOL_GPL(svc_shutdown_net); /* * Destroy an RPC service. Should be called with appropriate locking to * protect the sv_nrthreads, sv_permsocks and sv_tempsocks. */ void svc_destroy(struct svc_serv *serv) { dprintk("svc: svc_destroy(%s, %d)\n", serv->sv_program->pg_name, serv->sv_nrthreads); if (serv->sv_nrthreads) { if (--(serv->sv_nrthreads) != 0) { svc_sock_update_bufs(serv); return; } } else printk("svc_destroy: no threads for serv=%p!\n", serv); del_timer_sync(&serv->sv_temptimer); /* * The last user is gone and thus all sockets have to be destroyed to * the point. Check this. */ BUG_ON(!list_empty(&serv->sv_permsocks)); BUG_ON(!list_empty(&serv->sv_tempsocks)); cache_clean_deferred(serv); if (svc_serv_is_pooled(serv)) svc_pool_map_put(); kfree(serv->sv_pools); kfree(serv); } EXPORT_SYMBOL_GPL(svc_destroy); /* * Allocate an RPC server's buffer space. * We allocate pages and place them in rq_pages. */ static int svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node) { unsigned int pages, arghi; /* bc_xprt uses fore channel allocated buffers */ if (svc_is_backchannel(rqstp)) return 1; pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply. * We assume one is at most one page */ arghi = 0; WARN_ON_ONCE(pages > RPCSVC_MAXPAGES); if (pages > RPCSVC_MAXPAGES) pages = RPCSVC_MAXPAGES; while (pages) { struct page *p = alloc_pages_node(node, GFP_KERNEL, 0); if (!p) break; rqstp->rq_pages[arghi++] = p; pages--; } return pages == 0; } /* * Release an RPC server buffer */ static void svc_release_buffer(struct svc_rqst *rqstp) { unsigned int i; for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++) if (rqstp->rq_pages[i]) put_page(rqstp->rq_pages[i]); } struct svc_rqst * svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node) { struct svc_rqst *rqstp; rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node); if (!rqstp) return rqstp; __set_bit(RQ_BUSY, &rqstp->rq_flags); spin_lock_init(&rqstp->rq_lock); rqstp->rq_server = serv; rqstp->rq_pool = pool; rqstp->rq_scratch_page = alloc_pages_node(node, GFP_KERNEL, 0); if (!rqstp->rq_scratch_page) goto out_enomem; rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node); if (!rqstp->rq_argp) goto out_enomem; rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node); if (!rqstp->rq_resp) goto out_enomem; if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node)) goto out_enomem; return rqstp; out_enomem: svc_rqst_free(rqstp); return NULL; } EXPORT_SYMBOL_GPL(svc_rqst_alloc); struct svc_rqst * svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) { struct svc_rqst *rqstp; rqstp = svc_rqst_alloc(serv, pool, node); if (!rqstp) return ERR_PTR(-ENOMEM); serv->sv_nrthreads++; spin_lock_bh(&pool->sp_lock); pool->sp_nrthreads++; list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads); spin_unlock_bh(&pool->sp_lock); return rqstp; } EXPORT_SYMBOL_GPL(svc_prepare_thread); /* * Choose a pool in which to create a new thread, for svc_set_num_threads */ static inline struct svc_pool * choose_pool(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state) { if (pool != NULL) return pool; return &serv->sv_pools[(*state)++ % serv->sv_nrpools]; } /* * Choose a thread to kill, for svc_set_num_threads */ static inline struct task_struct * choose_victim(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state) { unsigned int i; struct task_struct *task = NULL; if (pool != NULL) { spin_lock_bh(&pool->sp_lock); } else { /* choose a pool in round-robin fashion */ for (i = 0; i < serv->sv_nrpools; i++) { pool = &serv->sv_pools[--(*state) % serv->sv_nrpools]; spin_lock_bh(&pool->sp_lock); if (!list_empty(&pool->sp_all_threads)) goto found_pool; spin_unlock_bh(&pool->sp_lock); } return NULL; } found_pool: if (!list_empty(&pool->sp_all_threads)) { struct svc_rqst *rqstp; /* * Remove from the pool->sp_all_threads list * so we don't try to kill it again. */ rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all); set_bit(RQ_VICTIM, &rqstp->rq_flags); list_del_rcu(&rqstp->rq_all); task = rqstp->rq_task; } spin_unlock_bh(&pool->sp_lock); return task; } /* create new threads */ static int svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) { struct svc_rqst *rqstp; struct task_struct *task; struct svc_pool *chosen_pool; unsigned int state = serv->sv_nrthreads-1; int node; do { nrservs--; chosen_pool = choose_pool(serv, pool, &state); node = svc_pool_map_get_node(chosen_pool->sp_id); rqstp = svc_prepare_thread(serv, chosen_pool, node); if (IS_ERR(rqstp)) return PTR_ERR(rqstp); __module_get(serv->sv_ops->svo_module); task = kthread_create_on_node(serv->sv_ops->svo_function, rqstp, node, "%s", serv->sv_name); if (IS_ERR(task)) { module_put(serv->sv_ops->svo_module); svc_exit_thread(rqstp); return PTR_ERR(task); } rqstp->rq_task = task; if (serv->sv_nrpools > 1) svc_pool_map_set_cpumask(task, chosen_pool->sp_id); svc_sock_update_bufs(serv); wake_up_process(task); } while (nrservs > 0); return 0; } /* destroy old threads */ static int svc_signal_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) { struct task_struct *task; unsigned int state = serv->sv_nrthreads-1; /* destroy old threads */ do { task = choose_victim(serv, pool, &state); if (task == NULL) break; send_sig(SIGINT, task, 1); nrservs++; } while (nrservs < 0); return 0; } /* * Create or destroy enough new threads to make the number * of threads the given number. If `pool' is non-NULL, applies * only to threads in that pool, otherwise round-robins between * all pools. Caller must ensure that mutual exclusion between this and * server startup or shutdown. * * Destroying threads relies on the service threads filling in * rqstp->rq_task, which only the nfs ones do. Assumes the serv * has been created using svc_create_pooled(). * * Based on code that used to be in nfsd_svc() but tweaked * to be pool-aware. */ int svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) { if (pool == NULL) { /* The -1 assumes caller has done a svc_get() */ nrservs -= (serv->sv_nrthreads-1); } else { spin_lock_bh(&pool->sp_lock); nrservs -= pool->sp_nrthreads; spin_unlock_bh(&pool->sp_lock); } if (nrservs > 0) return svc_start_kthreads(serv, pool, nrservs); if (nrservs < 0) return svc_signal_kthreads(serv, pool, nrservs); return 0; } EXPORT_SYMBOL_GPL(svc_set_num_threads); /* destroy old threads */ static int svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) { struct task_struct *task; unsigned int state = serv->sv_nrthreads-1; /* destroy old threads */ do { task = choose_victim(serv, pool, &state); if (task == NULL) break; kthread_stop(task); nrservs++; } while (nrservs < 0); return 0; } int svc_set_num_threads_sync(struct svc_serv *serv, struct svc_pool *pool, int nrservs) { if (pool == NULL) { /* The -1 assumes caller has done a svc_get() */ nrservs -= (serv->sv_nrthreads-1); } else { spin_lock_bh(&pool->sp_lock); nrservs -= pool->sp_nrthreads; spin_unlock_bh(&pool->sp_lock); } if (nrservs > 0) return svc_start_kthreads(serv, pool, nrservs); if (nrservs < 0) return svc_stop_kthreads(serv, pool, nrservs); return 0; } EXPORT_SYMBOL_GPL(svc_set_num_threads_sync); /* * Called from a server thread as it's exiting. Caller must hold the "service * mutex" for the service. */ void svc_rqst_free(struct svc_rqst *rqstp) { svc_release_buffer(rqstp); if (rqstp->rq_scratch_page) put_page(rqstp->rq_scratch_page); kfree(rqstp->rq_resp); kfree(rqstp->rq_argp); kfree(rqstp->rq_auth_data); kfree_rcu(rqstp, rq_rcu_head); } EXPORT_SYMBOL_GPL(svc_rqst_free); void svc_exit_thread(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; struct svc_pool *pool = rqstp->rq_pool; spin_lock_bh(&pool->sp_lock); pool->sp_nrthreads--; if (!test_and_set_bit(RQ_VICTIM, &rqstp->rq_flags)) list_del_rcu(&rqstp->rq_all); spin_unlock_bh(&pool->sp_lock); svc_rqst_free(rqstp); /* Release the server */ if (serv) svc_destroy(serv); } EXPORT_SYMBOL_GPL(svc_exit_thread); /* * Register an "inet" protocol family netid with the local * rpcbind daemon via an rpcbind v4 SET request. * * No netconfig infrastructure is available in the kernel, so * we map IP_ protocol numbers to netids by hand. * * Returns zero on success; a negative errno value is returned * if any error occurs. */ static int __svc_rpcb_register4(struct net *net, const u32 program, const u32 version, const unsigned short protocol, const unsigned short port) { const struct sockaddr_in sin = { .sin_family = AF_INET, .sin_addr.s_addr = htonl(INADDR_ANY), .sin_port = htons(port), }; const char *netid; int error; switch (protocol) { case IPPROTO_UDP: netid = RPCBIND_NETID_UDP; break; case IPPROTO_TCP: netid = RPCBIND_NETID_TCP; break; default: return -ENOPROTOOPT; } error = rpcb_v4_register(net, program, version, (const struct sockaddr *)&sin, netid); /* * User space didn't support rpcbind v4, so retry this * registration request with the legacy rpcbind v2 protocol. */ if (error == -EPROTONOSUPPORT) error = rpcb_register(net, program, version, protocol, port); return error; } #if IS_ENABLED(CONFIG_IPV6) /* * Register an "inet6" protocol family netid with the local * rpcbind daemon via an rpcbind v4 SET request. * * No netconfig infrastructure is available in the kernel, so * we map IP_ protocol numbers to netids by hand. * * Returns zero on success; a negative errno value is returned * if any error occurs. */ static int __svc_rpcb_register6(struct net *net, const u32 program, const u32 version, const unsigned short protocol, const unsigned short port) { const struct sockaddr_in6 sin6 = { .sin6_family = AF_INET6, .sin6_addr = IN6ADDR_ANY_INIT, .sin6_port = htons(port), }; const char *netid; int error; switch (protocol) { case IPPROTO_UDP: netid = RPCBIND_NETID_UDP6; break; case IPPROTO_TCP: netid = RPCBIND_NETID_TCP6; break; default: return -ENOPROTOOPT; } error = rpcb_v4_register(net, program, version, (const struct sockaddr *)&sin6, netid); /* * User space didn't support rpcbind version 4, so we won't * use a PF_INET6 listener. */ if (error == -EPROTONOSUPPORT) error = -EAFNOSUPPORT; return error; } #endif /* IS_ENABLED(CONFIG_IPV6) */ /* * Register a kernel RPC service via rpcbind version 4. * * Returns zero on success; a negative errno value is returned * if any error occurs. */ static int __svc_register(struct net *net, const char *progname, const u32 program, const u32 version, const int family, const unsigned short protocol, const unsigned short port) { int error = -EAFNOSUPPORT; switch (family) { case PF_INET: error = __svc_rpcb_register4(net, program, version, protocol, port); break; #if IS_ENABLED(CONFIG_IPV6) case PF_INET6: error = __svc_rpcb_register6(net, program, version, protocol, port); #endif } trace_svc_register(progname, version, protocol, port, family, error); return error; } int svc_rpcbind_set_version(struct net *net, const struct svc_program *progp, u32 version, int family, unsigned short proto, unsigned short port) { return __svc_register(net, progp->pg_name, progp->pg_prog, version, family, proto, port); } EXPORT_SYMBOL_GPL(svc_rpcbind_set_version); int svc_generic_rpcbind_set(struct net *net, const struct svc_program *progp, u32 version, int family, unsigned short proto, unsigned short port) { const struct svc_version *vers = progp->pg_vers[version]; int error; if (vers == NULL) return 0; if (vers->vs_hidden) { trace_svc_noregister(progp->pg_name, version, proto, port, family, 0); return 0; } /* * Don't register a UDP port if we need congestion * control. */ if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP) return 0; error = svc_rpcbind_set_version(net, progp, version, family, proto, port); return (vers->vs_rpcb_optnl) ? 0 : error; } EXPORT_SYMBOL_GPL(svc_generic_rpcbind_set); /** * svc_register - register an RPC service with the local portmapper * @serv: svc_serv struct for the service to register * @net: net namespace for the service to register * @family: protocol family of service's listener socket * @proto: transport protocol number to advertise * @port: port to advertise * * Service is registered for any address in the passed-in protocol family */ int svc_register(const struct svc_serv *serv, struct net *net, const int family, const unsigned short proto, const unsigned short port) { struct svc_program *progp; unsigned int i; int error = 0; WARN_ON_ONCE(proto == 0 && port == 0); if (proto == 0 && port == 0) return -EINVAL; for (progp = serv->sv_program; progp; progp = progp->pg_next) { for (i = 0; i < progp->pg_nvers; i++) { error = progp->pg_rpcbind_set(net, progp, i, family, proto, port); if (error < 0) { printk(KERN_WARNING "svc: failed to register " "%sv%u RPC service (errno %d).\n", progp->pg_name, i, -error); break; } } } return error; } /* * If user space is running rpcbind, it should take the v4 UNSET * and clear everything for this [program, version]. If user space * is running portmap, it will reject the v4 UNSET, but won't have * any "inet6" entries anyway. So a PMAP_UNSET should be sufficient * in this case to clear all existing entries for [program, version]. */ static void __svc_unregister(struct net *net, const u32 program, const u32 version, const char *progname) { int error; error = rpcb_v4_register(net, program, version, NULL, ""); /* * User space didn't support rpcbind v4, so retry this * request with the legacy rpcbind v2 protocol. */ if (error == -EPROTONOSUPPORT) error = rpcb_register(net, program, version, 0, 0); trace_svc_unregister(progname, version, error); } /* * All netids, bind addresses and ports registered for [program, version] * are removed from the local rpcbind database (if the service is not * hidden) to make way for a new instance of the service. * * The result of unregistration is reported via dprintk for those who want * verification of the result, but is otherwise not important. */ static void svc_unregister(const struct svc_serv *serv, struct net *net) { struct svc_program *progp; unsigned long flags; unsigned int i; clear_thread_flag(TIF_SIGPENDING); for (progp = serv->sv_program; progp; progp = progp->pg_next) { for (i = 0; i < progp->pg_nvers; i++) { if (progp->pg_vers[i] == NULL) continue; if (progp->pg_vers[i]->vs_hidden) continue; __svc_unregister(net, progp->pg_prog, i, progp->pg_name); } } spin_lock_irqsave(¤t->sighand->siglock, flags); recalc_sigpending(); spin_unlock_irqrestore(¤t->sighand->siglock, flags); } /* * dprintk the given error with the address of the client that caused it. */ #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) static __printf(2, 3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) { struct va_format vaf; va_list args; char buf[RPC_MAX_ADDRBUFLEN]; va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; dprintk("svc: %s: %pV", svc_print_addr(rqstp, buf, sizeof(buf)), &vaf); va_end(args); } #else static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {} #endif __be32 svc_return_autherr(struct svc_rqst *rqstp, __be32 auth_err) { set_bit(RQ_AUTHERR, &rqstp->rq_flags); return auth_err; } EXPORT_SYMBOL_GPL(svc_return_autherr); static __be32 svc_get_autherr(struct svc_rqst *rqstp, __be32 *statp) { if (test_and_clear_bit(RQ_AUTHERR, &rqstp->rq_flags)) return *statp; return rpc_auth_ok; } static int svc_generic_dispatch(struct svc_rqst *rqstp, __be32 *statp) { struct kvec *argv = &rqstp->rq_arg.head[0]; struct kvec *resv = &rqstp->rq_res.head[0]; const struct svc_procedure *procp = rqstp->rq_procinfo; /* * Decode arguments * XXX: why do we ignore the return value? */ if (procp->pc_decode && !procp->pc_decode(rqstp, argv->iov_base)) { *statp = rpc_garbage_args; return 1; } *statp = procp->pc_func(rqstp); if (*statp == rpc_drop_reply || test_bit(RQ_DROPME, &rqstp->rq_flags)) return 0; if (test_bit(RQ_AUTHERR, &rqstp->rq_flags)) return 1; if (*statp != rpc_success) return 1; /* Encode reply */ if (procp->pc_encode && !procp->pc_encode(rqstp, resv->iov_base + resv->iov_len)) { dprintk("svc: failed to encode reply\n"); /* serv->sv_stats->rpcsystemerr++; */ *statp = rpc_system_err; } return 1; } __be32 svc_generic_init_request(struct svc_rqst *rqstp, const struct svc_program *progp, struct svc_process_info *ret) { const struct svc_version *versp = NULL; /* compiler food */ const struct svc_procedure *procp = NULL; if (rqstp->rq_vers >= progp->pg_nvers ) goto err_bad_vers; versp = progp->pg_vers[rqstp->rq_vers]; if (!versp) goto err_bad_vers; /* * Some protocol versions (namely NFSv4) require some form of * congestion control. (See RFC 7530 section 3.1 paragraph 2) * In other words, UDP is not allowed. We mark those when setting * up the svc_xprt, and verify that here. * * The spec is not very clear about what error should be returned * when someone tries to access a server that is listening on UDP * for lower versions. RPC_PROG_MISMATCH seems to be the closest * fit. */ if (versp->vs_need_cong_ctrl && rqstp->rq_xprt && !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags)) goto err_bad_vers; if (rqstp->rq_proc >= versp->vs_nproc) goto err_bad_proc; rqstp->rq_procinfo = procp = &versp->vs_proc[rqstp->rq_proc]; if (!procp) goto err_bad_proc; /* Initialize storage for argp and resp */ memset(rqstp->rq_argp, 0, procp->pc_argsize); memset(rqstp->rq_resp, 0, procp->pc_ressize); /* Bump per-procedure stats counter */ versp->vs_count[rqstp->rq_proc]++; ret->dispatch = versp->vs_dispatch; return rpc_success; err_bad_vers: ret->mismatch.lovers = progp->pg_lovers; ret->mismatch.hivers = progp->pg_hivers; return rpc_prog_mismatch; err_bad_proc: return rpc_proc_unavail; } EXPORT_SYMBOL_GPL(svc_generic_init_request); /* * Common routine for processing the RPC request. */ static int svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv) { struct svc_program *progp; const struct svc_procedure *procp = NULL; struct svc_serv *serv = rqstp->rq_server; struct svc_process_info process; __be32 *statp; u32 prog, vers; __be32 rpc_stat; int auth_res; __be32 *reply_statp; rpc_stat = rpc_success; if (argv->iov_len < 6*4) goto err_short_len; /* Will be turned off by GSS integrity and privacy services */ set_bit(RQ_SPLICE_OK, &rqstp->rq_flags); /* Will be turned off only when NFSv4 Sessions are used */ set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags); clear_bit(RQ_DROPME, &rqstp->rq_flags); svc_putu32(resv, rqstp->rq_xid); vers = svc_getnl(argv); /* First words of reply: */ svc_putnl(resv, 1); /* REPLY */ if (vers != 2) /* RPC version number */ goto err_bad_rpc; /* Save position in case we later decide to reject: */ reply_statp = resv->iov_base + resv->iov_len; svc_putnl(resv, 0); /* ACCEPT */ rqstp->rq_prog = prog = svc_getnl(argv); /* program number */ rqstp->rq_vers = svc_getnl(argv); /* version number */ rqstp->rq_proc = svc_getnl(argv); /* procedure number */ for (progp = serv->sv_program; progp; progp = progp->pg_next) if (prog == progp->pg_prog) break; /* * Decode auth data, and add verifier to reply buffer. * We do this before anything else in order to get a decent * auth verifier. */ auth_res = svc_authenticate(rqstp); /* Also give the program a chance to reject this call: */ if (auth_res == SVC_OK && progp) auth_res = progp->pg_authenticate(rqstp); if (auth_res != SVC_OK) trace_svc_authenticate(rqstp, auth_res); switch (auth_res) { case SVC_OK: break; case SVC_GARBAGE: goto err_garbage; case SVC_SYSERR: rpc_stat = rpc_system_err; goto err_bad; case SVC_DENIED: goto err_bad_auth; case SVC_CLOSE: goto close; case SVC_DROP: goto dropit; case SVC_COMPLETE: goto sendit; } if (progp == NULL) goto err_bad_prog; rpc_stat = progp->pg_init_request(rqstp, progp, &process); switch (rpc_stat) { case rpc_success: break; case rpc_prog_unavail: goto err_bad_prog; case rpc_prog_mismatch: goto err_bad_vers; case rpc_proc_unavail: goto err_bad_proc; } procp = rqstp->rq_procinfo; /* Should this check go into the dispatcher? */ if (!procp || !procp->pc_func) goto err_bad_proc; /* Syntactic check complete */ serv->sv_stats->rpccnt++; trace_svc_process(rqstp, progp->pg_name); /* Build the reply header. */ statp = resv->iov_base +resv->iov_len; svc_putnl(resv, RPC_SUCCESS); /* un-reserve some of the out-queue now that we have a * better idea of reply size */ if (procp->pc_xdrressize) svc_reserve_auth(rqstp, procp->pc_xdrressize<<2); /* Call the function that processes the request. */ if (!process.dispatch) { if (!svc_generic_dispatch(rqstp, statp)) goto release_dropit; if (*statp == rpc_garbage_args) goto err_garbage; rqstp->rq_auth_stat = svc_get_autherr(rqstp, statp); if (rqstp->rq_auth_stat != rpc_auth_ok) goto err_release_bad_auth; } else { dprintk("svc: calling dispatcher\n"); if (!process.dispatch(rqstp, statp)) goto release_dropit; /* Release reply info */ } /* Check RPC status result */ if (*statp != rpc_success) resv->iov_len = ((void*)statp) - resv->iov_base + 4; /* Release reply info */ if (procp->pc_release) procp->pc_release(rqstp); if (procp->pc_encode == NULL) goto dropit; sendit: if (svc_authorise(rqstp)) goto close_xprt; return 1; /* Caller can now send it */ release_dropit: if (procp->pc_release) procp->pc_release(rqstp); dropit: svc_authorise(rqstp); /* doesn't hurt to call this twice */ dprintk("svc: svc_process dropit\n"); return 0; close: svc_authorise(rqstp); close_xprt: if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags)) svc_close_xprt(rqstp->rq_xprt); dprintk("svc: svc_process close\n"); return 0; err_short_len: svc_printk(rqstp, "short len %zd, dropping request\n", argv->iov_len); goto close_xprt; err_bad_rpc: serv->sv_stats->rpcbadfmt++; svc_putnl(resv, 1); /* REJECT */ svc_putnl(resv, 0); /* RPC_MISMATCH */ svc_putnl(resv, 2); /* Only RPCv2 supported */ svc_putnl(resv, 2); goto sendit; err_release_bad_auth: if (procp->pc_release) procp->pc_release(rqstp); err_bad_auth: dprintk("svc: authentication failed (%d)\n", be32_to_cpu(rqstp->rq_auth_stat)); serv->sv_stats->rpcbadauth++; /* Restore write pointer to location of accept status: */ xdr_ressize_check(rqstp, reply_statp); svc_putnl(resv, 1); /* REJECT */ svc_putnl(resv, 1); /* AUTH_ERROR */ svc_putu32(resv, rqstp->rq_auth_stat); /* status */ goto sendit; err_bad_prog: dprintk("svc: unknown program %d\n", prog); serv->sv_stats->rpcbadfmt++; svc_putnl(resv, RPC_PROG_UNAVAIL); goto sendit; err_bad_vers: svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n", rqstp->rq_vers, rqstp->rq_prog, progp->pg_name); serv->sv_stats->rpcbadfmt++; svc_putnl(resv, RPC_PROG_MISMATCH); svc_putnl(resv, process.mismatch.lovers); svc_putnl(resv, process.mismatch.hivers); goto sendit; err_bad_proc: svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc); serv->sv_stats->rpcbadfmt++; svc_putnl(resv, RPC_PROC_UNAVAIL); goto sendit; err_garbage: svc_printk(rqstp, "failed to decode args\n"); rpc_stat = rpc_garbage_args; err_bad: serv->sv_stats->rpcbadfmt++; svc_putnl(resv, ntohl(rpc_stat)); goto sendit; } /* * Process the RPC request. */ int svc_process(struct svc_rqst *rqstp) { struct kvec *argv = &rqstp->rq_arg.head[0]; struct kvec *resv = &rqstp->rq_res.head[0]; struct svc_serv *serv = rqstp->rq_server; u32 dir; /* * Setup response xdr_buf. * Initially it has just one page */ rqstp->rq_next_page = &rqstp->rq_respages[1]; resv->iov_base = page_address(rqstp->rq_respages[0]); resv->iov_len = 0; rqstp->rq_res.pages = rqstp->rq_respages + 1; rqstp->rq_res.len = 0; rqstp->rq_res.page_base = 0; rqstp->rq_res.page_len = 0; rqstp->rq_res.buflen = PAGE_SIZE; rqstp->rq_res.tail[0].iov_base = NULL; rqstp->rq_res.tail[0].iov_len = 0; dir = svc_getnl(argv); if (dir != 0) { /* direction != CALL */ svc_printk(rqstp, "bad direction %d, dropping request\n", dir); serv->sv_stats->rpcbadfmt++; goto out_drop; } /* Returns 1 for send, 0 for drop */ if (likely(svc_process_common(rqstp, argv, resv))) return svc_send(rqstp); out_drop: svc_drop(rqstp); return 0; } EXPORT_SYMBOL_GPL(svc_process); #if defined(CONFIG_SUNRPC_BACKCHANNEL) /* * Process a backchannel RPC request that arrived over an existing * outbound connection */ int bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req, struct svc_rqst *rqstp) { struct kvec *argv = &rqstp->rq_arg.head[0]; struct kvec *resv = &rqstp->rq_res.head[0]; struct rpc_task *task; int proc_error; int error; dprintk("svc: %s(%p)\n", __func__, req); /* Build the svc_rqst used by the common processing routine */ rqstp->rq_xid = req->rq_xid; rqstp->rq_prot = req->rq_xprt->prot; rqstp->rq_server = serv; rqstp->rq_bc_net = req->rq_xprt->xprt_net; rqstp->rq_addrlen = sizeof(req->rq_xprt->addr); memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen); memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg)); memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res)); /* Adjust the argument buffer length */ rqstp->rq_arg.len = req->rq_private_buf.len; if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) { rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len; rqstp->rq_arg.page_len = 0; } else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len) rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; else rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len; /* reset result send buffer "put" position */ resv->iov_len = 0; /* * Skip the next two words because they've already been * processed in the transport */ svc_getu32(argv); /* XID */ svc_getnl(argv); /* CALLDIR */ /* Parse and execute the bc call */ proc_error = svc_process_common(rqstp, argv, resv); atomic_dec(&req->rq_xprt->bc_slot_count); if (!proc_error) { /* Processing error: drop the request */ xprt_free_bc_request(req); error = -EINVAL; goto out; } /* Finally, send the reply synchronously */ memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf)); task = rpc_run_bc_task(req); if (IS_ERR(task)) { error = PTR_ERR(task); goto out; } WARN_ON_ONCE(atomic_read(&task->tk_count) != 1); error = task->tk_status; rpc_put_task(task); out: dprintk("svc: %s(), error=%d\n", __func__, error); return error; } EXPORT_SYMBOL_GPL(bc_svc_process); #endif /* CONFIG_SUNRPC_BACKCHANNEL */ /* * Return (transport-specific) limit on the rpc payload. */ u32 svc_max_payload(const struct svc_rqst *rqstp) { u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload; if (rqstp->rq_server->sv_max_payload < max) max = rqstp->rq_server->sv_max_payload; return max; } EXPORT_SYMBOL_GPL(svc_max_payload); /** * svc_encode_result_payload - mark a range of bytes as a result payload * @rqstp: svc_rqst to operate on * @offset: payload's byte offset in rqstp->rq_res * @length: size of payload, in bytes * * Returns zero on success, or a negative errno if a permanent * error occurred. */ int svc_encode_result_payload(struct svc_rqst *rqstp, unsigned int offset, unsigned int length) { return rqstp->rq_xprt->xpt_ops->xpo_result_payload(rqstp, offset, length); } EXPORT_SYMBOL_GPL(svc_encode_result_payload); /** * svc_fill_write_vector - Construct data argument for VFS write call * @rqstp: svc_rqst to operate on * @pages: list of pages containing data payload * @first: buffer containing first section of write payload * @total: total number of bytes of write payload * * Fills in rqstp::rq_vec, and returns the number of elements. */ unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct page **pages, struct kvec *first, size_t total) { struct kvec *vec = rqstp->rq_vec; unsigned int i; /* Some types of transport can present the write payload * entirely in rq_arg.pages. In this case, @first is empty. */ i = 0; if (first->iov_len) { vec[i].iov_base = first->iov_base; vec[i].iov_len = min_t(size_t, total, first->iov_len); total -= vec[i].iov_len; ++i; } while (total) { vec[i].iov_base = page_address(*pages); vec[i].iov_len = min_t(size_t, total, PAGE_SIZE); total -= vec[i].iov_len; ++i; ++pages; } WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec)); return i; } EXPORT_SYMBOL_GPL(svc_fill_write_vector); /** * svc_fill_symlink_pathname - Construct pathname argument for VFS symlink call * @rqstp: svc_rqst to operate on * @first: buffer containing first section of pathname * @p: buffer containing remaining section of pathname * @total: total length of the pathname argument * * The VFS symlink API demands a NUL-terminated pathname in mapped memory. * Returns pointer to a NUL-terminated string, or an ERR_PTR. Caller must free * the returned string. */ char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first, void *p, size_t total) { size_t len, remaining; char *result, *dst; result = kmalloc(total + 1, GFP_KERNEL); if (!result) return ERR_PTR(-ESERVERFAULT); dst = result; remaining = total; len = min_t(size_t, total, first->iov_len); if (len) { memcpy(dst, first->iov_base, len); dst += len; remaining -= len; } if (remaining) { len = min_t(size_t, remaining, PAGE_SIZE); memcpy(dst, p, len); dst += len; } *dst = '\0'; /* Sanity check: Linux doesn't allow the pathname argument to * contain a NUL byte. */ if (strlen(result) != total) { kfree(result); return ERR_PTR(-EINVAL); } return result; } EXPORT_SYMBOL_GPL(svc_fill_symlink_pathname);