[linux-block.git] / fs / nfs / callback.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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/sched/signal.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/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;
};

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_xprt_create(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_xprt_create(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);
	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);
	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 == nrservs)
		return 0;

	ret = svc_set_num_threads(serv, NULL, nrservs);
	if (ret) {
		svc_set_num_threads(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_xprt_destroy_all(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 struct svc_serv *nfs_callback_create_svc(int minorversion)
{
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	int (*threadfn)(void *data);
	struct svc_serv *serv;

	/*
	 * Check whether we're already up and running.
	 */
	if (cb_info->serv)
		return svc_get(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);

	threadfn = nfs4_callback_svc;
#if defined(CONFIG_NFS_V4_1)
	if (minorversion)
		threadfn = nfs41_callback_svc;
#else
	if (minorversion)
		return ERR_PTR(-ENOTSUPP);
#endif
	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE,
			  threadfn);
	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++;
err_net:
	if (!cb_info->users)
		cb_info->serv = NULL;
	svc_put(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);
		svc_set_num_threads(serv, NULL, 0);
		svc_put(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)
{
	rqstp->rq_auth_stat = rpc_autherr_badcred;

	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;
	}

	rqstp->rq_auth_stat = rpc_auth_ok;
	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,
};
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/nfs/callback.c
	4	*
	5	* Copyright (C) 2004 Trond Myklebust
	6	*
	7	* NFSv4 callback handling
	8	*/
	9
1da177e4 LT	10	#include <linux/completion.h>
	11	#include <linux/ip.h>
	12	#include <linux/module.h>
3f07c014	13	#include <linux/sched/signal.h>
1da177e4 LT	14	#include <linux/sunrpc/svc.h>
	15	#include <linux/sunrpc/svcsock.h>
	16	#include <linux/nfs_fs.h>
758201e2	17	#include <linux/errno.h>
353ab6e9	18	#include <linux/mutex.h>
83144186	19	#include <linux/freezer.h>
945b34a7	20	#include <linux/sunrpc/svcauth_gss.h>
a43cde94	21	#include <linux/sunrpc/bc_xprt.h>
14c85021 ACM	22
	23	#include <net/inet_sock.h>
	24
4ce79717	25	#include "nfs4_fs.h"
1da177e4	26	#include "callback.h"
24c8dbbb	27	#include "internal.h"
bbe0a3aa	28	#include "netns.h"
1da177e4 LT	29
	30	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	31
	32	struct nfs_callback_data {
	33	unsigned int users;
a43cde94	34	struct svc_serv *serv;
1da177e4 LT	35	};
1da177e4 LT	36
e82dc22d	37	static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
353ab6e9	38	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	39	static struct svc_program nfs4_callback_program;
1da177e4 LT	40
c946556b SK	41	static int nfs4_callback_up_net(struct svc_serv serv, struct net net)
c946556b SK	42	{
4df493a2	43	const struct cred *cred = current_cred();
c946556b	44	int ret;
bbe0a3aa	45	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b	46
352ad314 CL	47	ret = svc_xprt_create(serv, "tcp", net, PF_INET,
	48	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS,
	49	cred);
c946556b SK	50	if (ret <= 0)
c946556b SK	51	goto out_err;
bbe0a3aa	52	nn->nfs_callback_tcpport = ret;
e4949e4b VA	53	dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
e4949e4b VA	54	nn->nfs_callback_tcpport, PF_INET, net->ns.inum);
c946556b	55
352ad314 CL	56	ret = svc_xprt_create(serv, "tcp", net, PF_INET6,
	57	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS,
	58	cred);
c946556b	59	if (ret > 0) {
29dcc16a	60	nn->nfs_callback_tcpport6 = ret;
91bd2ffa	61	dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
e4949e4b	62	nn->nfs_callback_tcpport6, PF_INET6, net->ns.inum);
c946556b SK	63	} else if (ret != -EAFNOSUPPORT)
	64	goto out_err;
	65	return 0;
	66
	67	out_err:
	68	return (ret) ? ret : -ENOMEM;
	69	}
	70
1da177e4	71	/*
e82dc22d	72	* This is the NFSv4 callback kernel thread.
1da177e4	73	*/
a277e33c	74	static int
71468513	75	nfs4_callback_svc(void *vrqstp)
1da177e4	76	{
5b444cc9	77	int err;
a277e33c	78	struct svc_rqst *rqstp = vrqstp;
1da177e4	79
83144186	80	set_freezable();
1da177e4	81
ed6473dd TM	82	while (!kthread_freezable_should_stop(NULL)) {
	83
	84	if (signal_pending(current))
	85	flush_signals(current);
1da177e4 LT	86	/*
	87	* Listen for a request on the socket
	88	*/
6fb2b47f	89	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
5b444cc9	90	if (err == -EAGAIN \|\| err == -EINTR)
1da177e4	91	continue;
6fb2b47f	92	svc_process(rqstp);
1da177e4	93	}
f49169c9	94
ed6473dd	95	svc_exit_thread(rqstp);
a277e33c	96	return 0;
1da177e4 LT	97	}
1da177e4 LT	98
a43cde94 RL	99	#if defined(CONFIG_NFS_V4_1)
	100	/*
	101	* The callback service for NFSv4.1 callbacks
	102	*/
	103	static int
	104	nfs41_callback_svc(void *vrqstp)
	105	{
	106	struct svc_rqst *rqstp = vrqstp;
	107	struct svc_serv *serv = rqstp->rq_server;
	108	struct rpc_rqst *req;
	109	int error;
	110	DEFINE_WAIT(wq);
	111
	112	set_freezable();
	113
ed6473dd TM	114	while (!kthread_freezable_should_stop(NULL)) {
	115
	116	if (signal_pending(current))
	117	flush_signals(current);
25d280aa	118
5d05e54a	119	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
a43cde94 RL	120	spin_lock_bh(&serv->sv_cb_lock);
	121	if (!list_empty(&serv->sv_cb_list)) {
	122	req = list_first_entry(&serv->sv_cb_list,
	123	struct rpc_rqst, rq_bc_list);
	124	list_del(&req->rq_bc_list);
	125	spin_unlock_bh(&serv->sv_cb_lock);
6ffa30d3	126	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94 RL	127	dprintk("Invoking bc_svc_process()\n");
	128	error = bc_svc_process(serv, req, rqstp);
	129	dprintk("bc_svc_process() returned w/ error code= %d\n",
	130	error);
	131	} else {
	132	spin_unlock_bh(&serv->sv_cb_lock);
ed6473dd TM	133	if (!kthread_should_stop())
ed6473dd TM	134	schedule();
6ffa30d3	135	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94	136	}
a43cde94	137	}
f49169c9	138
ed6473dd	139	svc_exit_thread(rqstp);
a43cde94 RL	140	return 0;
	141	}
	142
a43cde94	143	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	144	struct svc_serv *serv)
a43cde94 RL	145	{
a43cde94 RL	146	if (minorversion)
691c457a SK	147	/*
	148	* Save the svc_serv in the transport so that it can
	149	* be referenced when the session backchannel is initialized
	150	*/
	151	xprt->bc_serv = serv;
a43cde94 RL	152	}
a43cde94 RL	153	#else
a43cde94	154	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	155	struct svc_serv *serv)
a43cde94 RL	156	{
	157	}
	158	#endif /* CONFIG_NFS_V4_1 */
	159
8e246144 SK	160	static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
	161	struct svc_serv *serv)
	162	{
5405fc44	163	int nrservs = nfs_callback_nr_threads;
8e246144	164	int ret;
8e246144 SK	165
	166	nfs_callback_bc_serv(minorversion, xprt, serv);
	167
5405fc44 TM	168	if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
	169	nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
	170
ec52361d	171	if (serv->sv_nrthreads == nrservs)
23c20ecd SK	172	return 0;
23c20ecd SK	173
3ebdbe52	174	ret = svc_set_num_threads(serv, NULL, nrservs);
bb6aeba7	175	if (ret) {
3ebdbe52	176	svc_set_num_threads(serv, NULL, 0);
e9b7e917	177	return ret;
8e246144 SK	178	}
	179	dprintk("nfs_callback_up: service started\n");
	180	return 0;
	181	}
	182
b3d19c51 SK	183	static void nfs_callback_down_net(u32 minorversion, struct svc_serv serv, struct net net)
	184	{
	185	struct nfs_net *nn = net_generic(net, nfs_net_id);
	186
	187	if (--nn->cb_users[minorversion])
	188	return;
	189
e4949e4b	190	dprintk("NFS: destroy per-net callback data; net=%x\n", net->ns.inum);
c7d7ec8f	191	svc_xprt_destroy_all(serv, net);
b3d19c51 SK	192	}
b3d19c51 SK	193
76566773 CL	194	static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
76566773 CL	195	struct net net, struct rpc_xprt xprt)
c946556b	196	{
b3d19c51	197	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	198	int ret;
c946556b SK	199
b3d19c51 SK	200	if (nn->cb_users[minorversion]++)
	201	return 0;
	202
e4949e4b	203	dprintk("NFS: create per-net callback data; net=%x\n", net->ns.inum);
c946556b SK	204
	205	ret = svc_bind(serv, net);
	206	if (ret < 0) {
	207	printk(KERN_WARNING "NFS: bind callback service failed\n");
	208	goto err_bind;
	209	}
	210
a289ce53	211	ret = 0;
d55b352b	212	if (!IS_ENABLED(CONFIG_NFS_V4_1) \|\| minorversion == 0)
76566773	213	ret = nfs4_callback_up_net(serv, net);
a289ce53	214	else if (xprt->ops->bc_setup)
0ad30ff6	215	set_bc_enabled(serv);
a289ce53 VA	216	else
a289ce53 VA	217	ret = -EPROTONOSUPPORT;
c946556b SK	218
	219	if (ret < 0) {
	220	printk(KERN_ERR "NFS: callback service start failed\n");
	221	goto err_socks;
	222	}
	223	return 0;
	224
	225	err_socks:
	226	svc_rpcb_cleanup(serv, net);
	227	err_bind:
98b0f80c	228	nn->cb_users[minorversion]--;
23c20ecd	229	dprintk("NFS: Couldn't create callback socket: err = %d; "
e4949e4b	230	"net = %x\n", ret, net->ns.inum);
c946556b SK	231	return ret;
	232	}
	233
dd018428 SK	234	static struct svc_serv *nfs_callback_create_svc(int minorversion)
	235	{
	236	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
37902c63	237	int (threadfn)(void data);
dd018428 SK	238	struct svc_serv *serv;
	239
	240	/*
	241	* Check whether we're already up and running.
	242	*/
df5e49c8	243	if (cb_info->serv)
df5e49c8	244	return svc_get(cb_info->serv);
dd018428 SK	245
	246	/*
	247	* Sanity check: if there's no task,
	248	* we should be the first user ...
	249	*/
	250	if (cb_info->users)
	251	printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
	252	cb_info->users);
	253
37902c63 CL	254	threadfn = nfs4_callback_svc;
	255	#if defined(CONFIG_NFS_V4_1)
	256	if (minorversion)
	257	threadfn = nfs41_callback_svc;
	258	#else
	259	if (minorversion)
	260	return ERR_PTR(-ENOTSUPP);
	261	#endif
	262	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE,
	263	threadfn);
dd018428 SK	264	if (!serv) {
	265	printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
	266	return ERR_PTR(-ENOMEM);
	267	}
3b01c11e	268	cb_info->serv = serv;
dd018428 SK	269	/* As there is only one thread we need to over-ride the
	270	* default maximum of 80 connections
	271	*/
	272	serv->sv_maxconn = 1024;
	273	dprintk("nfs_callback_create_svc: service created\n");
	274	return serv;
	275	}
	276
71468513 BH	277	/*
	278	* Bring up the callback thread if it is not already up.
	279	*/
	280	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	281	{
dd018428	282	struct svc_serv *serv;
e82dc22d	283	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
23c20ecd	284	int ret;
c946556b	285	struct net *net = xprt->xprt_net;
71468513 BH	286
71468513 BH	287	mutex_lock(&nfs_callback_mutex);
dd018428 SK	288
	289	serv = nfs_callback_create_svc(minorversion);
	290	if (IS_ERR(serv)) {
	291	ret = PTR_ERR(serv);
	292	goto err_create;
	293	}
	294
76566773	295	ret = nfs_callback_up_net(minorversion, serv, net, xprt);
c946556b SK	296	if (ret < 0)
c946556b SK	297	goto err_net;
9793f7c8	298
8e246144 SK	299	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	300	if (ret < 0)
	301	goto err_start;
a277e33c	302
23c20ecd	303	cb_info->users++;
23c20ecd	304	err_net:
3b01c11e TM	305	if (!cb_info->users)
3b01c11e TM	306	cb_info->serv = NULL;
8c62d127	307	svc_put(serv);
dd018428	308	err_create:
353ab6e9	309	mutex_unlock(&nfs_callback_mutex);
1da177e4	310	return ret;
8e246144 SK	311
8e246144 SK	312	err_start:
b3d19c51	313	nfs_callback_down_net(minorversion, serv, net);
23c20ecd SK	314	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
23c20ecd SK	315	goto err_net;
1da177e4 LT	316	}
	317
	318	/*
5afc597c	319	* Kill the callback thread if it's no longer being used.
1da177e4	320	*/
c8ceb412	321	void nfs_callback_down(int minorversion, struct net *net)
1da177e4	322	{
e82dc22d	323	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
bb6aeba7	324	struct svc_serv *serv;
e82dc22d	325
353ab6e9	326	mutex_lock(&nfs_callback_mutex);
bb6aeba7 TM	327	serv = cb_info->serv;
bb6aeba7 TM	328	nfs_callback_down_net(minorversion, serv, net);
e82dc22d	329	cb_info->users--;
3b01c11e	330	if (cb_info->users == 0) {
bb6aeba7	331	svc_get(serv);
3ebdbe52	332	svc_set_num_threads(serv, NULL, 0);
8c62d127	333	svc_put(serv);
1dc42e04	334	dprintk("nfs_callback_down: service destroyed\n");
e82dc22d	335	cb_info->serv = NULL;
5afc597c	336	}
353ab6e9	337	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	338	}
1da177e4 LT	339
778be232 AA	340	/* Boolean check of RPC_AUTH_GSS principal */
	341	int
	342	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	343	{
03a4e1f6	344	char *p = rqstp->rq_cred.cr_principal;
945b34a7	345
778be232 AA	346	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	347	return 1;
	348
ece0de63 AA	349	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	350	if (clp->cl_minorversion != 0)
778be232	351	return 0;
945b34a7 OK	352	/*
	353	* It might just be a normal user principal, in which case
	354	* userspace won't bother to tell us the name at all.
	355	*/
	356	if (p == NULL)
778be232	357	return 0;
945b34a7	358
f11b2a1c JL	359	/*
	360	* Did we get the acceptor from userland during the SETCLIENID
	361	* negotiation?
	362	*/
	363	if (clp->cl_acceptor)
	364	return !strcmp(p, clp->cl_acceptor);
	365
	366	/*
	367	* Otherwise try to verify it using the cl_hostname. Note that this
	368	* doesn't work if a non-canonical hostname was used in the devname.
	369	*/
	370
945b34a7 OK	371	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	372
	373	if (memcmp(p, "nfs@", 4) != 0)
778be232	374	return 0;
945b34a7	375	p += 4;
4e0038b6	376	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	377	return 0;
778be232 AA	378	return 1;
945b34a7 OK	379	}
945b34a7 OK	380
778be232 AA	381	/*
	382	* pg_authenticate method for nfsv4 callback threads.
	383	*
	384	* The authflavor has been negotiated, so an incorrect flavor is a server
6f02dc88	385	* bug. Deny packets with incorrect authflavor.
778be232 AA	386	*
	387	* All other checking done after NFS decoding where the nfs_client can be
	388	* found in nfs4_callback_compound
	389	*/
1da177e4 LT	390	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	391	{
5c2465df CL	392	rqstp->rq_auth_stat = rpc_autherr_badcred;
5c2465df CL	393
1da177e4	394	switch (rqstp->rq_authop->flavour) {
778be232 AA	395	case RPC_AUTH_NULL:
778be232 AA	396	if (rqstp->rq_proc != CB_NULL)
6f02dc88	397	return SVC_DENIED;
778be232 AA	398	break;
	399	case RPC_AUTH_GSS:
	400	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	401	if (svc_is_backchannel(rqstp))
6f02dc88	402	return SVC_DENIED;
1da177e4	403	}
5c2465df CL	404
5c2465df CL	405	rqstp->rq_auth_stat = rpc_auth_ok;
778be232	406	return SVC_OK;
1da177e4 LT	407	}
	408
	409	/*
	410	* Define NFS4 callback program
	411	*/
e9679189	412	static const struct svc_version *nfs4_callback_version[] = {
1da177e4	413	[1] = &nfs4_callback_version1,
07bccc2d	414	[4] = &nfs4_callback_version4,
1da177e4 LT	415	};
	416
	417	static struct svc_stat nfs4_callback_stats;
	418
	419	static struct svc_program nfs4_callback_program = {
	420	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	421	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	422	.pg_vers = nfs4_callback_version, /* version table */
	423	.pg_name = "NFSv4 callback", /* service name */
	424	.pg_class = "nfs", /* authentication class */
	425	.pg_stats = &nfs4_callback_stats,
	426	.pg_authenticate = nfs_callback_authenticate,
8e5b6773	427	.pg_init_request = svc_generic_init_request,
642ee6b2	428	.pg_rpcbind_set = svc_generic_rpcbind_set,
1da177e4	429	};