| /* |
| * 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/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" |
| |
| #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; |
| |
| unsigned int nfs_callback_set_tcpport; |
| unsigned short nfs_callback_tcpport; |
| unsigned short nfs_callback_tcpport6; |
| #define NFS_CALLBACK_MAXPORTNR (65535U) |
| |
| static int param_set_portnr(const char *val, const struct kernel_param *kp) |
| { |
| unsigned long num; |
| int ret; |
| |
| if (!val) |
| return -EINVAL; |
| ret = strict_strtoul(val, 0, &num); |
| if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR) |
| return -EINVAL; |
| *((unsigned int *)kp->arg) = num; |
| return 0; |
| } |
| static struct kernel_param_ops param_ops_portnr = { |
| .set = param_set_portnr, |
| .get = param_get_uint, |
| }; |
| #define param_check_portnr(name, p) __param_check(name, p, unsigned int); |
| |
| module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644); |
| |
| /* |
| * This is the NFSv4 callback kernel thread. |
| */ |
| static int |
| nfs4_callback_svc(void *vrqstp) |
| { |
| int err, preverr = 0; |
| 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) { |
| preverr = err; |
| continue; |
| } |
| if (err < 0) { |
| if (err != preverr) { |
| printk(KERN_WARNING "NFS: %s: unexpected error " |
| "from svc_recv (%d)\n", __func__, err); |
| preverr = err; |
| } |
| schedule_timeout_uninterruptible(HZ); |
| continue; |
| } |
| preverr = err; |
| svc_process(rqstp); |
| } |
| return 0; |
| } |
| |
| /* |
| * Prepare to bring up the NFSv4 callback service |
| */ |
| static struct svc_rqst * |
| nfs4_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt) |
| { |
| int ret; |
| |
| ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET, |
| nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); |
| if (ret <= 0) |
| goto out_err; |
| nfs_callback_tcpport = ret; |
| dprintk("NFS: Callback listener port = %u (af %u)\n", |
| nfs_callback_tcpport, PF_INET); |
| |
| ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET6, |
| nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); |
| if (ret > 0) { |
| nfs_callback_tcpport6 = ret; |
| dprintk("NFS: Callback listener port = %u (af %u)\n", |
| nfs_callback_tcpport6, PF_INET6); |
| } else if (ret == -EAFNOSUPPORT) |
| ret = 0; |
| else |
| goto out_err; |
| |
| return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE); |
| |
| out_err: |
| if (ret == 0) |
| ret = -ENOMEM; |
| return ERR_PTR(ret); |
| } |
| |
| #if defined(CONFIG_NFS_V4_1) |
| /* |
| * 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); |
| finish_wait(&serv->sv_cb_waitq, &wq); |
| 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); |
| } |
| flush_signals(current); |
| } |
| return 0; |
| } |
| |
| /* |
| * Bring up the NFSv4.1 callback service |
| */ |
| static struct svc_rqst * |
| nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt) |
| { |
| struct svc_rqst *rqstp; |
| int ret; |
| |
| /* |
| * 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 |
| */ |
| ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0, |
| SVC_SOCK_ANONYMOUS); |
| if (ret < 0) { |
| rqstp = ERR_PTR(ret); |
| goto out; |
| } |
| |
| /* |
| * Save the svc_serv in the transport so that it can |
| * be referenced when the session backchannel is initialized |
| */ |
| xprt->bc_serv = serv; |
| |
| 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; |
| } |
| out: |
| dprintk("--> %s return %ld\n", __func__, |
| IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0); |
| return rqstp; |
| } |
| |
| static inline int nfs_minorversion_callback_svc_setup(u32 minorversion, |
| struct svc_serv *serv, struct rpc_xprt *xprt, |
| struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) |
| { |
| if (minorversion) { |
| *rqstpp = nfs41_callback_up(serv, xprt); |
| *callback_svc = nfs41_callback_svc; |
| } |
| return minorversion; |
| } |
| |
| static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, |
| struct nfs_callback_data *cb_info) |
| { |
| if (minorversion) |
| xprt->bc_serv = cb_info->serv; |
| } |
| #else |
| static inline int nfs_minorversion_callback_svc_setup(u32 minorversion, |
| struct svc_serv *serv, struct rpc_xprt *xprt, |
| struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) |
| { |
| return 0; |
| } |
| |
| static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, |
| struct nfs_callback_data *cb_info) |
| { |
| } |
| #endif /* CONFIG_NFS_V4_1 */ |
| |
| /* |
| * 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 = NULL; |
| 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 = 0; |
| int minorversion_setup; |
| struct net *net = &init_net; |
| |
| mutex_lock(&nfs_callback_mutex); |
| if (cb_info->users++ || cb_info->task != NULL) { |
| nfs_callback_bc_serv(minorversion, xprt, cb_info); |
| goto out; |
| } |
| serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL); |
| if (!serv) { |
| ret = -ENOMEM; |
| goto out_err; |
| } |
| |
| ret = svc_bind(serv, net); |
| if (ret < 0) { |
| printk(KERN_WARNING "NFS: bind callback service failed\n"); |
| goto out_err; |
| } |
| |
| minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion, |
| serv, xprt, &rqstp, &callback_svc); |
| if (!minorversion_setup) { |
| /* v4.0 callback setup */ |
| rqstp = nfs4_callback_up(serv, xprt); |
| callback_svc = nfs4_callback_svc; |
| } |
| |
| if (IS_ERR(rqstp)) { |
| ret = PTR_ERR(rqstp); |
| goto out_err; |
| } |
| |
| 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; |
| goto out_err; |
| } |
| out: |
| /* |
| * 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. |
| */ |
| if (serv) |
| svc_destroy(serv); |
| mutex_unlock(&nfs_callback_mutex); |
| return ret; |
| out_err: |
| dprintk("NFS: Couldn't create callback socket or server thread; " |
| "err = %d\n", ret); |
| cb_info->users--; |
| if (serv) |
| svc_shutdown_net(serv, net); |
| goto out; |
| } |
| |
| /* |
| * Kill the callback thread if it's no longer being used. |
| */ |
| void nfs_callback_down(int minorversion) |
| { |
| struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; |
| |
| mutex_lock(&nfs_callback_mutex); |
| cb_info->users--; |
| if (cb_info->users == 0 && cb_info->task != NULL) { |
| kthread_stop(cb_info->task); |
| svc_shutdown_net(cb_info->serv, &init_net); |
| svc_exit_thread(cb_info->rqst); |
| 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 = svc_gss_principal(rqstp); |
| |
| 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, |
| }; |