[linux.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/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;
};

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 %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);
	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 = -EPROTONOSUPPORT;
	if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
		ret = nfs4_callback_up_net(serv, net);
	else if (xprt->ops->bc_up)
		ret = xprt->ops->bc_up(serv, net);

	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,
};
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>
a277e33c	20	#include <linux/kthread.h>
945b34a7	21	#include <linux/sunrpc/svcauth_gss.h>
a43cde94	22	#include <linux/sunrpc/bc_xprt.h>
14c85021 ACM	23
	24	#include <net/inet_sock.h>
	25
4ce79717	26	#include "nfs4_fs.h"
1da177e4	27	#include "callback.h"
24c8dbbb	28	#include "internal.h"
bbe0a3aa	29	#include "netns.h"
1da177e4 LT	30
	31	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	32
	33	struct nfs_callback_data {
	34	unsigned int users;
a43cde94	35	struct svc_serv *serv;
1da177e4 LT	36	};
1da177e4 LT	37
e82dc22d	38	static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
353ab6e9	39	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	40	static struct svc_program nfs4_callback_program;
1da177e4 LT	41
c946556b SK	42	static int nfs4_callback_up_net(struct svc_serv serv, struct net net)
	43	{
	44	int ret;
bbe0a3aa	45	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	46
	47	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
	48	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	49	if (ret <= 0)
	50	goto out_err;
bbe0a3aa	51	nn->nfs_callback_tcpport = ret;
e4949e4b VA	52	dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
e4949e4b VA	53	nn->nfs_callback_tcpport, PF_INET, net->ns.inum);
c946556b SK	54
	55	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
	56	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	57	if (ret > 0) {
29dcc16a	58	nn->nfs_callback_tcpport6 = ret;
e4949e4b VA	59	dprintk("NFS: Callback listener port = %u (af %u, net %x\n",
e4949e4b VA	60	nn->nfs_callback_tcpport6, PF_INET6, net->ns.inum);
c946556b SK	61	} else if (ret != -EAFNOSUPPORT)
	62	goto out_err;
	63	return 0;
	64
	65	out_err:
	66	return (ret) ? ret : -ENOMEM;
	67	}
	68
1da177e4	69	/*
e82dc22d	70	* This is the NFSv4 callback kernel thread.
1da177e4	71	*/
a277e33c	72	static int
71468513	73	nfs4_callback_svc(void *vrqstp)
1da177e4	74	{
5b444cc9	75	int err;
a277e33c	76	struct svc_rqst *rqstp = vrqstp;
1da177e4	77
83144186	78	set_freezable();
1da177e4	79
ed6473dd TM	80	while (!kthread_freezable_should_stop(NULL)) {
	81
	82	if (signal_pending(current))
	83	flush_signals(current);
1da177e4 LT	84	/*
	85	* Listen for a request on the socket
	86	*/
6fb2b47f	87	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
5b444cc9	88	if (err == -EAGAIN \|\| err == -EINTR)
1da177e4	89	continue;
6fb2b47f	90	svc_process(rqstp);
1da177e4	91	}
ed6473dd TM	92	svc_exit_thread(rqstp);
ed6473dd TM	93	module_put_and_exit(0);
a277e33c	94	return 0;
1da177e4 LT	95	}
1da177e4 LT	96
a43cde94 RL	97	#if defined(CONFIG_NFS_V4_1)
	98	/*
	99	* The callback service for NFSv4.1 callbacks
	100	*/
	101	static int
	102	nfs41_callback_svc(void *vrqstp)
	103	{
	104	struct svc_rqst *rqstp = vrqstp;
	105	struct svc_serv *serv = rqstp->rq_server;
	106	struct rpc_rqst *req;
	107	int error;
	108	DEFINE_WAIT(wq);
	109
	110	set_freezable();
	111
ed6473dd TM	112	while (!kthread_freezable_should_stop(NULL)) {
	113
	114	if (signal_pending(current))
	115	flush_signals(current);
25d280aa	116
5d05e54a	117	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
a43cde94 RL	118	spin_lock_bh(&serv->sv_cb_lock);
	119	if (!list_empty(&serv->sv_cb_list)) {
	120	req = list_first_entry(&serv->sv_cb_list,
	121	struct rpc_rqst, rq_bc_list);
	122	list_del(&req->rq_bc_list);
	123	spin_unlock_bh(&serv->sv_cb_lock);
6ffa30d3	124	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94 RL	125	dprintk("Invoking bc_svc_process()\n");
	126	error = bc_svc_process(serv, req, rqstp);
	127	dprintk("bc_svc_process() returned w/ error code= %d\n",
	128	error);
	129	} else {
	130	spin_unlock_bh(&serv->sv_cb_lock);
ed6473dd TM	131	if (!kthread_should_stop())
ed6473dd TM	132	schedule();
6ffa30d3	133	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94	134	}
a43cde94	135	}
ed6473dd TM	136	svc_exit_thread(rqstp);
ed6473dd TM	137	module_put_and_exit(0);
a43cde94 RL	138	return 0;
	139	}
	140
a43cde94	141	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	142	struct svc_serv *serv)
a43cde94 RL	143	{
a43cde94 RL	144	if (minorversion)
691c457a SK	145	/*
	146	* Save the svc_serv in the transport so that it can
	147	* be referenced when the session backchannel is initialized
	148	*/
	149	xprt->bc_serv = serv;
a43cde94 RL	150	}
a43cde94 RL	151	#else
a43cde94	152	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	153	struct svc_serv *serv)
a43cde94 RL	154	{
	155	}
	156	#endif /* CONFIG_NFS_V4_1 */
	157
8e246144 SK	158	static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
	159	struct svc_serv *serv)
	160	{
5405fc44	161	int nrservs = nfs_callback_nr_threads;
8e246144	162	int ret;
8e246144 SK	163
	164	nfs_callback_bc_serv(minorversion, xprt, serv);
	165
5405fc44 TM	166	if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
	167	nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
	168
bb6aeba7	169	if (serv->sv_nrthreads-1 == nrservs)
23c20ecd SK	170	return 0;
23c20ecd SK	171
bb6aeba7 TM	172	ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
	173	if (ret) {
	174	serv->sv_ops->svo_setup(serv, NULL, 0);
e9b7e917	175	return ret;
8e246144 SK	176	}
	177	dprintk("nfs_callback_up: service started\n");
	178	return 0;
	179	}
	180
b3d19c51 SK	181	static void nfs_callback_down_net(u32 minorversion, struct svc_serv serv, struct net net)
	182	{
	183	struct nfs_net *nn = net_generic(net, nfs_net_id);
	184
	185	if (--nn->cb_users[minorversion])
	186	return;
	187
e4949e4b	188	dprintk("NFS: destroy per-net callback data; net=%x\n", net->ns.inum);
b3d19c51 SK	189	svc_shutdown_net(serv, net);
	190	}
	191
76566773 CL	192	static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
76566773 CL	193	struct net net, struct rpc_xprt xprt)
c946556b	194	{
b3d19c51	195	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	196	int ret;
c946556b SK	197
b3d19c51 SK	198	if (nn->cb_users[minorversion]++)
	199	return 0;
	200
e4949e4b	201	dprintk("NFS: create per-net callback data; net=%x\n", net->ns.inum);
c946556b SK	202
	203	ret = svc_bind(serv, net);
	204	if (ret < 0) {
	205	printk(KERN_WARNING "NFS: bind callback service failed\n");
	206	goto err_bind;
	207	}
	208
76566773	209	ret = -EPROTONOSUPPORT;
d55b352b	210	if (!IS_ENABLED(CONFIG_NFS_V4_1) \|\| minorversion == 0)
76566773 CL	211	ret = nfs4_callback_up_net(serv, net);
	212	else if (xprt->ops->bc_up)
	213	ret = xprt->ops->bc_up(serv, net);
c946556b SK	214
	215	if (ret < 0) {
	216	printk(KERN_ERR "NFS: callback service start failed\n");
	217	goto err_socks;
	218	}
	219	return 0;
	220
	221	err_socks:
	222	svc_rpcb_cleanup(serv, net);
	223	err_bind:
98b0f80c	224	nn->cb_users[minorversion]--;
23c20ecd	225	dprintk("NFS: Couldn't create callback socket: err = %d; "
e4949e4b	226	"net = %x\n", ret, net->ns.inum);
c946556b SK	227	return ret;
	228	}
	229
afea5657	230	static const struct svc_serv_ops nfs40_cb_sv_ops = {
f4b52bb0	231	.svo_function = nfs4_callback_svc,
b9e13cdf	232	.svo_enqueue_xprt = svc_xprt_do_enqueue,
ed6473dd	233	.svo_setup = svc_set_num_threads_sync,
f4b52bb0 TM	234	.svo_module = THIS_MODULE,
	235	};
	236	#if defined(CONFIG_NFS_V4_1)
afea5657	237	static const struct svc_serv_ops nfs41_cb_sv_ops = {
f4b52bb0 TM	238	.svo_function = nfs41_callback_svc,
f4b52bb0 TM	239	.svo_enqueue_xprt = svc_xprt_do_enqueue,
ed6473dd	240	.svo_setup = svc_set_num_threads_sync,
f4b52bb0	241	.svo_module = THIS_MODULE,
ea126e74 JL	242	};
ea126e74 JL	243
afea5657	244	static const struct svc_serv_ops *nfs4_cb_sv_ops[] = {
f4b52bb0 TM	245	[0] = &nfs40_cb_sv_ops,
	246	[1] = &nfs41_cb_sv_ops,
	247	};
	248	#else
afea5657	249	static const struct svc_serv_ops *nfs4_cb_sv_ops[] = {
f4b52bb0 TM	250	[0] = &nfs40_cb_sv_ops,
	251	[1] = NULL,
	252	};
	253	#endif
	254
dd018428 SK	255	static struct svc_serv *nfs_callback_create_svc(int minorversion)
	256	{
	257	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
afea5657	258	const struct svc_serv_ops *sv_ops;
dd018428 SK	259	struct svc_serv *serv;
	260
	261	/*
	262	* Check whether we're already up and running.
	263	*/
3b01c11e	264	if (cb_info->serv) {
dd018428 SK	265	/*
	266	* Note: increase service usage, because later in case of error
	267	* svc_destroy() will be called.
	268	*/
	269	svc_get(cb_info->serv);
	270	return cb_info->serv;
	271	}
	272
f4b52bb0 TM	273	switch (minorversion) {
	274	case 0:
	275	sv_ops = nfs4_cb_sv_ops[0];
	276	break;
	277	default:
	278	sv_ops = nfs4_cb_sv_ops[1];
	279	}
	280
	281	if (sv_ops == NULL)
	282	return ERR_PTR(-ENOTSUPP);
	283
dd018428 SK	284	/*
	285	* Sanity check: if there's no task,
	286	* we should be the first user ...
	287	*/
	288	if (cb_info->users)
	289	printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
	290	cb_info->users);
	291
df807fff	292	serv = svc_create_pooled(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
dd018428 SK	293	if (!serv) {
	294	printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
	295	return ERR_PTR(-ENOMEM);
	296	}
3b01c11e	297	cb_info->serv = serv;
dd018428 SK	298	/* As there is only one thread we need to over-ride the
	299	* default maximum of 80 connections
	300	*/
	301	serv->sv_maxconn = 1024;
	302	dprintk("nfs_callback_create_svc: service created\n");
	303	return serv;
	304	}
	305
71468513 BH	306	/*
	307	* Bring up the callback thread if it is not already up.
	308	*/
	309	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	310	{
dd018428	311	struct svc_serv *serv;
e82dc22d	312	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
23c20ecd	313	int ret;
c946556b	314	struct net *net = xprt->xprt_net;
71468513 BH	315
71468513 BH	316	mutex_lock(&nfs_callback_mutex);
dd018428 SK	317
	318	serv = nfs_callback_create_svc(minorversion);
	319	if (IS_ERR(serv)) {
	320	ret = PTR_ERR(serv);
	321	goto err_create;
	322	}
	323
76566773	324	ret = nfs_callback_up_net(minorversion, serv, net, xprt);
c946556b SK	325	if (ret < 0)
c946556b SK	326	goto err_net;
9793f7c8	327
8e246144 SK	328	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	329	if (ret < 0)
	330	goto err_start;
a277e33c	331
23c20ecd	332	cb_info->users++;
8e60029f JL	333	/*
8e60029f JL	334	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	335	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	336	* on both success and failure so that the refcount is 1 when the
	337	* thread exits.
	338	*/
23c20ecd	339	err_net:
3b01c11e TM	340	if (!cb_info->users)
3b01c11e TM	341	cb_info->serv = NULL;
dd018428 SK	342	svc_destroy(serv);
dd018428 SK	343	err_create:
353ab6e9	344	mutex_unlock(&nfs_callback_mutex);
1da177e4	345	return ret;
8e246144 SK	346
8e246144 SK	347	err_start:
b3d19c51	348	nfs_callback_down_net(minorversion, serv, net);
23c20ecd SK	349	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
23c20ecd SK	350	goto err_net;
1da177e4 LT	351	}
	352
	353	/*
5afc597c	354	* Kill the callback thread if it's no longer being used.
1da177e4	355	*/
c8ceb412	356	void nfs_callback_down(int minorversion, struct net *net)
1da177e4	357	{
e82dc22d	358	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
bb6aeba7	359	struct svc_serv *serv;
e82dc22d	360
353ab6e9	361	mutex_lock(&nfs_callback_mutex);
bb6aeba7 TM	362	serv = cb_info->serv;
bb6aeba7 TM	363	nfs_callback_down_net(minorversion, serv, net);
e82dc22d	364	cb_info->users--;
3b01c11e	365	if (cb_info->users == 0) {
bb6aeba7 TM	366	svc_get(serv);
	367	serv->sv_ops->svo_setup(serv, NULL, 0);
	368	svc_destroy(serv);
1dc42e04	369	dprintk("nfs_callback_down: service destroyed\n");
e82dc22d	370	cb_info->serv = NULL;
5afc597c	371	}
353ab6e9	372	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	373	}
1da177e4 LT	374
778be232 AA	375	/* Boolean check of RPC_AUTH_GSS principal */
	376	int
	377	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	378	{
03a4e1f6	379	char *p = rqstp->rq_cred.cr_principal;
945b34a7	380
778be232 AA	381	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	382	return 1;
	383
ece0de63 AA	384	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	385	if (clp->cl_minorversion != 0)
778be232	386	return 0;
945b34a7 OK	387	/*
	388	* It might just be a normal user principal, in which case
	389	* userspace won't bother to tell us the name at all.
	390	*/
	391	if (p == NULL)
778be232	392	return 0;
945b34a7	393
f11b2a1c JL	394	/*
	395	* Did we get the acceptor from userland during the SETCLIENID
	396	* negotiation?
	397	*/
	398	if (clp->cl_acceptor)
	399	return !strcmp(p, clp->cl_acceptor);
	400
	401	/*
	402	* Otherwise try to verify it using the cl_hostname. Note that this
	403	* doesn't work if a non-canonical hostname was used in the devname.
	404	*/
	405
945b34a7 OK	406	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	407
	408	if (memcmp(p, "nfs@", 4) != 0)
778be232	409	return 0;
945b34a7	410	p += 4;
4e0038b6	411	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	412	return 0;
778be232 AA	413	return 1;
945b34a7 OK	414	}
945b34a7 OK	415
778be232 AA	416	/*
	417	* pg_authenticate method for nfsv4 callback threads.
	418	*
	419	* The authflavor has been negotiated, so an incorrect flavor is a server
6f02dc88	420	* bug. Deny packets with incorrect authflavor.
778be232 AA	421	*
	422	* All other checking done after NFS decoding where the nfs_client can be
	423	* found in nfs4_callback_compound
	424	*/
1da177e4 LT	425	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	426	{
1da177e4	427	switch (rqstp->rq_authop->flavour) {
778be232 AA	428	case RPC_AUTH_NULL:
778be232 AA	429	if (rqstp->rq_proc != CB_NULL)
6f02dc88	430	return SVC_DENIED;
778be232 AA	431	break;
	432	case RPC_AUTH_GSS:
	433	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	434	if (svc_is_backchannel(rqstp))
6f02dc88	435	return SVC_DENIED;
1da177e4	436	}
778be232	437	return SVC_OK;
1da177e4 LT	438	}
	439
	440	/*
	441	* Define NFS4 callback program
	442	*/
e9679189	443	static const struct svc_version *nfs4_callback_version[] = {
1da177e4	444	[1] = &nfs4_callback_version1,
07bccc2d	445	[4] = &nfs4_callback_version4,
1da177e4 LT	446	};
	447
	448	static struct svc_stat nfs4_callback_stats;
	449
	450	static struct svc_program nfs4_callback_program = {
	451	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	452	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	453	.pg_vers = nfs4_callback_version, /* version table */
	454	.pg_name = "NFSv4 callback", /* service name */
	455	.pg_class = "nfs", /* authentication class */
	456	.pg_stats = &nfs4_callback_stats,
	457	.pg_authenticate = nfs_callback_authenticate,
	458	};