/* * linux/fs/nfs/callback.c * * Copyright (C) 2004 Trond Myklebust * * NFSv4 callback handling */ #include <linux/completion.h> #include <linux/ip.h> #include <linux/module.h> #include <linux/sunrpc/svc.h> #include <linux/sunrpc/svcsock.h> #include <linux/nfs_fs.h> #include <linux/errno.h> #include <linux/mutex.h> #include <linux/freezer.h> #include <linux/kthread.h> #include <linux/sunrpc/svcauth_gss.h> #include <linux/sunrpc/bc_xprt.h> #include <net/inet_sock.h> #include "nfs4_fs.h" #include "callback.h" #include "internal.h" #include "netns.h" #define NFSDBG_FACILITY NFSDBG_CALLBACK struct nfs_callback_data { unsigned int users; struct svc_serv *serv; struct svc_rqst *rqst; struct task_struct *task; }; static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1]; static DEFINE_MUTEX(nfs_callback_mutex); static struct svc_program nfs4_callback_program; static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net) { int ret; struct nfs_net *nn = net_generic(net, nfs_net_id); ret = svc_create_xprt(serv, "tcp", net, PF_INET, nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); if (ret <= 0) goto out_err; nn->nfs_callback_tcpport = ret; dprintk("NFS: Callback listener port = %u (af %u, net %p)\n", nn->nfs_callback_tcpport, PF_INET, net); ret = svc_create_xprt(serv, "tcp", net, PF_INET6, nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); if (ret > 0) { nn->nfs_callback_tcpport6 = ret; dprintk("NFS: Callback listener port = %u (af %u, net %p)\n", nn->nfs_callback_tcpport6, PF_INET6, net); } else if (ret != -EAFNOSUPPORT) goto out_err; return 0; out_err: return (ret) ? ret : -ENOMEM; } /* * This is the NFSv4 callback kernel thread. */ static int nfs4_callback_svc(void *vrqstp) { int err; struct svc_rqst *rqstp = vrqstp; set_freezable(); while (!kthread_should_stop()) { /* * Listen for a request on the socket */ err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); if (err == -EAGAIN || err == -EINTR) continue; svc_process(rqstp); } return 0; } /* * Prepare to bring up the NFSv4 callback service */ static struct svc_rqst * nfs4_callback_up(struct svc_serv *serv) { return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE); } #if defined(CONFIG_NFS_V4_1) static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net) { /* * Create an svc_sock for the back channel service that shares the * fore channel connection. * Returns the input port (0) and sets the svc_serv bc_xprt on success */ return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0, SVC_SOCK_ANONYMOUS); } /* * The callback service for NFSv4.1 callbacks */ static int nfs41_callback_svc(void *vrqstp) { struct svc_rqst *rqstp = vrqstp; struct svc_serv *serv = rqstp->rq_server; struct rpc_rqst *req; int error; DEFINE_WAIT(wq); set_freezable(); while (!kthread_should_stop()) { prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE); spin_lock_bh(&serv->sv_cb_lock); if (!list_empty(&serv->sv_cb_list)) { req = list_first_entry(&serv->sv_cb_list, struct rpc_rqst, rq_bc_list); list_del(&req->rq_bc_list); spin_unlock_bh(&serv->sv_cb_lock); dprintk("Invoking bc_svc_process()\n"); error = bc_svc_process(serv, req, rqstp); dprintk("bc_svc_process() returned w/ error code= %d\n", error); } else { spin_unlock_bh(&serv->sv_cb_lock); schedule(); } finish_wait(&serv->sv_cb_waitq, &wq); } return 0; } /* * Bring up the NFSv4.1 callback service */ static struct svc_rqst * nfs41_callback_up(struct svc_serv *serv) { struct svc_rqst *rqstp; INIT_LIST_HEAD(&serv->sv_cb_list); spin_lock_init(&serv->sv_cb_lock); init_waitqueue_head(&serv->sv_cb_waitq); rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE); if (IS_ERR(rqstp)) { svc_xprt_put(serv->sv_bc_xprt); serv->sv_bc_xprt = NULL; } dprintk("--> %s return %ld\n", __func__, IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0); return rqstp; } static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv, struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) { *rqstpp = nfs41_callback_up(serv); *callback_svc = nfs41_callback_svc; } static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, struct svc_serv *serv) { if (minorversion) /* * Save the svc_serv in the transport so that it can * be referenced when the session backchannel is initialized */ xprt->bc_serv = serv; } #else static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net) { return 0; } static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv, struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) { *rqstpp = ERR_PTR(-ENOTSUPP); *callback_svc = ERR_PTR(-ENOTSUPP); } static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, struct svc_serv *serv) { } #endif /* CONFIG_NFS_V4_1 */ static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt, struct svc_serv *serv) { struct svc_rqst *rqstp; int (*callback_svc)(void *vrqstp); struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; char svc_name[12]; int ret; nfs_callback_bc_serv(minorversion, xprt, serv); if (cb_info->task) return 0; switch (minorversion) { case 0: /* v4.0 callback setup */ rqstp = nfs4_callback_up(serv); callback_svc = nfs4_callback_svc; break; default: nfs_minorversion_callback_svc_setup(serv, &rqstp, &callback_svc); } if (IS_ERR(rqstp)) return PTR_ERR(rqstp); svc_sock_update_bufs(serv); sprintf(svc_name, "nfsv4.%u-svc", minorversion); cb_info->serv = serv; cb_info->rqst = rqstp; cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name); if (IS_ERR(cb_info->task)) { ret = PTR_ERR(cb_info->task); svc_exit_thread(cb_info->rqst); cb_info->rqst = NULL; cb_info->task = NULL; return ret; } dprintk("nfs_callback_up: service started\n"); return 0; } static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net) { struct nfs_net *nn = net_generic(net, nfs_net_id); if (--nn->cb_users[minorversion]) return; dprintk("NFS: destroy per-net callback data; net=%p\n", net); svc_shutdown_net(serv, net); } static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net) { struct nfs_net *nn = net_generic(net, nfs_net_id); int ret; if (nn->cb_users[minorversion]++) return 0; dprintk("NFS: create per-net callback data; net=%p\n", net); ret = svc_bind(serv, net); if (ret < 0) { printk(KERN_WARNING "NFS: bind callback service failed\n"); goto err_bind; } switch (minorversion) { case 0: ret = nfs4_callback_up_net(serv, net); break; case 1: ret = nfs41_callback_up_net(serv, net); break; default: printk(KERN_ERR "NFS: unknown callback version: %d\n", minorversion); ret = -EINVAL; break; } if (ret < 0) { printk(KERN_ERR "NFS: callback service start failed\n"); goto err_socks; } return 0; err_socks: svc_rpcb_cleanup(serv, net); err_bind: dprintk("NFS: Couldn't create callback socket: err = %d; " "net = %p\n", ret, net); return ret; } static struct svc_serv *nfs_callback_create_svc(int minorversion) { struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; struct svc_serv *serv; /* * Check whether we're already up and running. */ if (cb_info->task) { /* * Note: increase service usage, because later in case of error * svc_destroy() will be called. */ svc_get(cb_info->serv); return cb_info->serv; } /* * Sanity check: if there's no task, * we should be the first user ... */ if (cb_info->users) printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n", cb_info->users); serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL); if (!serv) { printk(KERN_ERR "nfs_callback_create_svc: create service failed\n"); return ERR_PTR(-ENOMEM); } /* As there is only one thread we need to over-ride the * default maximum of 80 connections */ serv->sv_maxconn = 1024; dprintk("nfs_callback_create_svc: service created\n"); return serv; } /* * Bring up the callback thread if it is not already up. */ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt) { struct svc_serv *serv; struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; int ret; struct net *net = xprt->xprt_net; mutex_lock(&nfs_callback_mutex); serv = nfs_callback_create_svc(minorversion); if (IS_ERR(serv)) { ret = PTR_ERR(serv); goto err_create; } ret = nfs_callback_up_net(minorversion, serv, net); if (ret < 0) goto err_net; ret = nfs_callback_start_svc(minorversion, xprt, serv); if (ret < 0) goto err_start; cb_info->users++; /* * svc_create creates the svc_serv with sv_nrthreads == 1, and then * svc_prepare_thread increments that. So we need to call svc_destroy * on both success and failure so that the refcount is 1 when the * thread exits. */ err_net: svc_destroy(serv); err_create: mutex_unlock(&nfs_callback_mutex); return ret; err_start: nfs_callback_down_net(minorversion, serv, net); dprintk("NFS: Couldn't create server thread; err = %d\n", ret); goto err_net; } /* * Kill the callback thread if it's no longer being used. */ void nfs_callback_down(int minorversion, struct net *net) { struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; mutex_lock(&nfs_callback_mutex); nfs_callback_down_net(minorversion, cb_info->serv, net); cb_info->users--; if (cb_info->users == 0 && cb_info->task != NULL) { kthread_stop(cb_info->task); dprintk("nfs_callback_down: service stopped\n"); svc_exit_thread(cb_info->rqst); dprintk("nfs_callback_down: service destroyed\n"); cb_info->serv = NULL; cb_info->rqst = NULL; cb_info->task = NULL; } mutex_unlock(&nfs_callback_mutex); } /* Boolean check of RPC_AUTH_GSS principal */ int check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp) { char *p = rqstp->rq_cred.cr_principal; if (rqstp->rq_authop->flavour != RPC_AUTH_GSS) return 1; /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */ if (clp->cl_minorversion != 0) return 0; /* * It might just be a normal user principal, in which case * userspace won't bother to tell us the name at all. */ if (p == NULL) return 0; /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */ if (memcmp(p, "nfs@", 4) != 0) return 0; p += 4; if (strcmp(p, clp->cl_hostname) != 0) return 0; return 1; } /* * pg_authenticate method for nfsv4 callback threads. * * The authflavor has been negotiated, so an incorrect flavor is a server * bug. Drop packets with incorrect authflavor. * * All other checking done after NFS decoding where the nfs_client can be * found in nfs4_callback_compound */ static int nfs_callback_authenticate(struct svc_rqst *rqstp) { switch (rqstp->rq_authop->flavour) { case RPC_AUTH_NULL: if (rqstp->rq_proc != CB_NULL) return SVC_DROP; break; case RPC_AUTH_GSS: /* No RPC_AUTH_GSS support yet in NFSv4.1 */ if (svc_is_backchannel(rqstp)) return SVC_DROP; } return SVC_OK; } /* * Define NFS4 callback program */ static struct svc_version *nfs4_callback_version[] = { [1] = &nfs4_callback_version1, [4] = &nfs4_callback_version4, }; static struct svc_stat nfs4_callback_stats; static struct svc_program nfs4_callback_program = { .pg_prog = NFS4_CALLBACK, /* RPC service number */ .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ .pg_vers = nfs4_callback_version, /* version table */ .pg_name = "NFSv4 callback", /* service name */ .pg_class = "nfs", /* authentication class */ .pg_stats = &nfs4_callback_stats, .pg_authenticate = nfs_callback_authenticate, };