From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- fs/nfs/callback.c | 465 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 465 insertions(+) create mode 100644 fs/nfs/callback.c (limited to 'fs/nfs/callback.c') diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c new file mode 100644 index 000000000..7817ad94a --- /dev/null +++ b/fs/nfs/callback.c @@ -0,0 +1,465 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/nfs/callback.c + * + * Copyright (C) 2004 Trond Myklebust + * + * NFSv4 callback handling + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#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; +}; + +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) +{ + const struct cred *cred = current_cred(); + 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, + cred); + if (ret <= 0) + goto out_err; + nn->nfs_callback_tcpport = ret; + dprintk("NFS: Callback listener port = %u (af %u, net %x)\n", + nn->nfs_callback_tcpport, PF_INET, net->ns.inum); + + ret = svc_create_xprt(serv, "tcp", net, PF_INET6, + nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS, + cred); + if (ret > 0) { + nn->nfs_callback_tcpport6 = ret; + dprintk("NFS: Callback listener port = %u (af %u, net %x)\n", + nn->nfs_callback_tcpport6, PF_INET6, net->ns.inum); + } 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_freezable_should_stop(NULL)) { + + if (signal_pending(current)) + flush_signals(current); + /* + * Listen for a request on the socket + */ + err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); + if (err == -EAGAIN || err == -EINTR) + continue; + svc_process(rqstp); + } + svc_exit_thread(rqstp); + module_put_and_exit(0); + return 0; +} + +#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_freezable_should_stop(NULL)) { + + if (signal_pending(current)) + flush_signals(current); + + 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); + if (!kthread_should_stop()) + schedule(); + finish_wait(&serv->sv_cb_waitq, &wq); + } + } + svc_exit_thread(rqstp); + module_put_and_exit(0); + return 0; +} + +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 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) +{ + int nrservs = nfs_callback_nr_threads; + int ret; + + nfs_callback_bc_serv(minorversion, xprt, serv); + + if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS) + nrservs = NFS4_MIN_NR_CALLBACK_THREADS; + + if (serv->sv_nrthreads-1 == nrservs) + return 0; + + ret = serv->sv_ops->svo_setup(serv, NULL, nrservs); + if (ret) { + serv->sv_ops->svo_setup(serv, NULL, 0); + 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=%x\n", net->ns.inum); + svc_shutdown_net(serv, net); +} + +static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, + struct net *net, struct rpc_xprt *xprt) +{ + 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=%x\n", net->ns.inum); + + ret = svc_bind(serv, net); + if (ret < 0) { + printk(KERN_WARNING "NFS: bind callback service failed\n"); + goto err_bind; + } + + ret = 0; + if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0) + ret = nfs4_callback_up_net(serv, net); + else if (xprt->ops->bc_setup) + set_bc_enabled(serv); + else + ret = -EPROTONOSUPPORT; + + 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: + nn->cb_users[minorversion]--; + dprintk("NFS: Couldn't create callback socket: err = %d; " + "net = %x\n", ret, net->ns.inum); + return ret; +} + +static const struct svc_serv_ops nfs40_cb_sv_ops = { + .svo_function = nfs4_callback_svc, + .svo_enqueue_xprt = svc_xprt_do_enqueue, + .svo_setup = svc_set_num_threads_sync, + .svo_module = THIS_MODULE, +}; +#if defined(CONFIG_NFS_V4_1) +static const struct svc_serv_ops nfs41_cb_sv_ops = { + .svo_function = nfs41_callback_svc, + .svo_enqueue_xprt = svc_xprt_do_enqueue, + .svo_setup = svc_set_num_threads_sync, + .svo_module = THIS_MODULE, +}; + +static const struct svc_serv_ops *nfs4_cb_sv_ops[] = { + [0] = &nfs40_cb_sv_ops, + [1] = &nfs41_cb_sv_ops, +}; +#else +static const struct svc_serv_ops *nfs4_cb_sv_ops[] = { + [0] = &nfs40_cb_sv_ops, + [1] = NULL, +}; +#endif + +static struct svc_serv *nfs_callback_create_svc(int minorversion) +{ + struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; + const struct svc_serv_ops *sv_ops; + struct svc_serv *serv; + + /* + * Check whether we're already up and running. + */ + if (cb_info->serv) { + /* + * Note: increase service usage, because later in case of error + * svc_destroy() will be called. + */ + svc_get(cb_info->serv); + return cb_info->serv; + } + + switch (minorversion) { + case 0: + sv_ops = nfs4_cb_sv_ops[0]; + break; + default: + sv_ops = nfs4_cb_sv_ops[1]; + } + + if (sv_ops == NULL) + return ERR_PTR(-ENOTSUPP); + + /* + * 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_pooled(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops); + if (!serv) { + printk(KERN_ERR "nfs_callback_create_svc: create service failed\n"); + return ERR_PTR(-ENOMEM); + } + cb_info->serv = serv; + /* 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, xprt); + 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: + if (!cb_info->users) + cb_info->serv = NULL; + 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]; + struct svc_serv *serv; + + mutex_lock(&nfs_callback_mutex); + serv = cb_info->serv; + nfs_callback_down_net(minorversion, serv, net); + cb_info->users--; + if (cb_info->users == 0) { + svc_get(serv); + serv->sv_ops->svo_setup(serv, NULL, 0); + svc_destroy(serv); + dprintk("nfs_callback_down: service destroyed\n"); + cb_info->serv = 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; + + /* + * Did we get the acceptor from userland during the SETCLIENID + * negotiation? + */ + if (clp->cl_acceptor) + return !strcmp(p, clp->cl_acceptor); + + /* + * Otherwise try to verify it using the cl_hostname. Note that this + * doesn't work if a non-canonical hostname was used in the devname. + */ + + /* 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. Deny 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_DENIED; + break; + case RPC_AUTH_GSS: + /* No RPC_AUTH_GSS support yet in NFSv4.1 */ + if (svc_is_backchannel(rqstp)) + return SVC_DENIED; + } + return SVC_OK; +} + +/* + * Define NFS4 callback program + */ +static const 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, + .pg_init_request = svc_generic_init_request, + .pg_rpcbind_set = svc_generic_rpcbind_set, +}; -- cgit v1.2.3