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

/*
 * 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;
};

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;
}

#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()) {
		if (try_to_freeze())
			continue;

		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;
}

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)
{
	const int nrservs = NFS4_NR_CALLBACK_THREADS;
	int ret;

	nfs_callback_bc_serv(minorversion, xprt, serv);

	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=%p\n", net);
	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=%p\n", net);

	ret = svc_bind(serv, net);
	if (ret < 0) {
		printk(KERN_WARNING "NFS: bind callback service failed\n");
		goto err_bind;
	}

	ret = -EPROTONOSUPPORT;
	if (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 = %p\n", ret, net);
	return ret;
}

static 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,
	.svo_module		= THIS_MODULE,
};
#if defined(CONFIG_NFS_V4_1)
static 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,
	.svo_module		= THIS_MODULE,
};

struct svc_serv_ops *nfs4_cb_sv_ops[] = {
	[0] = &nfs40_cb_sv_ops,
	[1] = &nfs41_cb_sv_ops,
};
#else
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];
	struct svc_serv *serv;
	struct svc_serv_ops *sv_ops;

	/*
	 * 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(&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 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
1da177e4 LT	1	/*
	2	* linux/fs/nfs/callback.c
	3	*
	4	* Copyright (C) 2004 Trond Myklebust
	5	*
	6	* NFSv4 callback handling
	7	*/
	8
1da177e4 LT	9	#include <linux/completion.h>
	10	#include <linux/ip.h>
	11	#include <linux/module.h>
1da177e4 LT	12	#include <linux/sunrpc/svc.h>
	13	#include <linux/sunrpc/svcsock.h>
	14	#include <linux/nfs_fs.h>
758201e2	15	#include <linux/errno.h>
353ab6e9	16	#include <linux/mutex.h>
83144186	17	#include <linux/freezer.h>
a277e33c	18	#include <linux/kthread.h>
945b34a7	19	#include <linux/sunrpc/svcauth_gss.h>
a43cde94	20	#include <linux/sunrpc/bc_xprt.h>
14c85021 ACM	21
	22	#include <net/inet_sock.h>
	23
4ce79717	24	#include "nfs4_fs.h"
1da177e4	25	#include "callback.h"
24c8dbbb	26	#include "internal.h"
bbe0a3aa	27	#include "netns.h"
1da177e4 LT	28
	29	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	30
	31	struct nfs_callback_data {
	32	unsigned int users;
a43cde94	33	struct svc_serv *serv;
1da177e4 LT	34	};
1da177e4 LT	35
e82dc22d	36	static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
353ab6e9	37	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	38	static struct svc_program nfs4_callback_program;
1da177e4 LT	39
c946556b SK	40	static int nfs4_callback_up_net(struct svc_serv serv, struct net net)
	41	{
	42	int ret;
bbe0a3aa	43	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	44
	45	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
	46	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	47	if (ret <= 0)
	48	goto out_err;
bbe0a3aa	49	nn->nfs_callback_tcpport = ret;
c946556b	50	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
bbe0a3aa	51	nn->nfs_callback_tcpport, PF_INET, net);
c946556b SK	52
	53	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
	54	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	55	if (ret > 0) {
29dcc16a	56	nn->nfs_callback_tcpport6 = ret;
c946556b	57	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
29dcc16a	58	nn->nfs_callback_tcpport6, PF_INET6, net);
c946556b SK	59	} else if (ret != -EAFNOSUPPORT)
	60	goto out_err;
	61	return 0;
	62
	63	out_err:
	64	return (ret) ? ret : -ENOMEM;
	65	}
	66
1da177e4	67	/*
e82dc22d	68	* This is the NFSv4 callback kernel thread.
1da177e4	69	*/
a277e33c	70	static int
71468513	71	nfs4_callback_svc(void *vrqstp)
1da177e4	72	{
5b444cc9	73	int err;
a277e33c	74	struct svc_rqst *rqstp = vrqstp;
1da177e4	75
83144186	76	set_freezable();
1da177e4	77
a277e33c	78	while (!kthread_should_stop()) {
1da177e4 LT	79	/*
	80	* Listen for a request on the socket
	81	*/
6fb2b47f	82	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
5b444cc9	83	if (err == -EAGAIN \|\| err == -EINTR)
1da177e4	84	continue;
6fb2b47f	85	svc_process(rqstp);
1da177e4	86	}
a277e33c	87	return 0;
1da177e4 LT	88	}
1da177e4 LT	89
a43cde94 RL	90	#if defined(CONFIG_NFS_V4_1)
	91	/*
	92	* The callback service for NFSv4.1 callbacks
	93	*/
	94	static int
	95	nfs41_callback_svc(void *vrqstp)
	96	{
	97	struct svc_rqst *rqstp = vrqstp;
	98	struct svc_serv *serv = rqstp->rq_server;
	99	struct rpc_rqst *req;
	100	int error;
	101	DEFINE_WAIT(wq);
	102
	103	set_freezable();
	104
a43cde94	105	while (!kthread_should_stop()) {
25d280aa JL	106	if (try_to_freeze())
	107	continue;
	108
5d05e54a	109	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
a43cde94 RL	110	spin_lock_bh(&serv->sv_cb_lock);
	111	if (!list_empty(&serv->sv_cb_list)) {
	112	req = list_first_entry(&serv->sv_cb_list,
	113	struct rpc_rqst, rq_bc_list);
	114	list_del(&req->rq_bc_list);
	115	spin_unlock_bh(&serv->sv_cb_lock);
6ffa30d3	116	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94 RL	117	dprintk("Invoking bc_svc_process()\n");
	118	error = bc_svc_process(serv, req, rqstp);
	119	dprintk("bc_svc_process() returned w/ error code= %d\n",
	120	error);
	121	} else {
	122	spin_unlock_bh(&serv->sv_cb_lock);
5d05e54a	123	schedule();
6ffa30d3	124	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94	125	}
5d05e54a	126	flush_signals(current);
a43cde94	127	}
a43cde94 RL	128	return 0;
	129	}
	130
a43cde94	131	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	132	struct svc_serv *serv)
a43cde94 RL	133	{
a43cde94 RL	134	if (minorversion)
691c457a SK	135	/*
	136	* Save the svc_serv in the transport so that it can
	137	* be referenced when the session backchannel is initialized
	138	*/
	139	xprt->bc_serv = serv;
a43cde94 RL	140	}
a43cde94 RL	141	#else
a43cde94	142	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	143	struct svc_serv *serv)
a43cde94 RL	144	{
	145	}
	146	#endif /* CONFIG_NFS_V4_1 */
	147
8e246144 SK	148	static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
	149	struct svc_serv *serv)
	150	{
bb6aeba7	151	const int nrservs = NFS4_NR_CALLBACK_THREADS;
8e246144	152	int ret;
8e246144 SK	153
	154	nfs_callback_bc_serv(minorversion, xprt, serv);
	155
bb6aeba7	156	if (serv->sv_nrthreads-1 == nrservs)
23c20ecd SK	157	return 0;
23c20ecd SK	158
bb6aeba7 TM	159	ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
	160	if (ret) {
	161	serv->sv_ops->svo_setup(serv, NULL, 0);
e9b7e917	162	return ret;
8e246144 SK	163	}
	164	dprintk("nfs_callback_up: service started\n");
	165	return 0;
	166	}
	167
b3d19c51 SK	168	static void nfs_callback_down_net(u32 minorversion, struct svc_serv serv, struct net net)
	169	{
	170	struct nfs_net *nn = net_generic(net, nfs_net_id);
	171
	172	if (--nn->cb_users[minorversion])
	173	return;
	174
	175	dprintk("NFS: destroy per-net callback data; net=%p\n", net);
	176	svc_shutdown_net(serv, net);
	177	}
	178
76566773 CL	179	static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
76566773 CL	180	struct net net, struct rpc_xprt xprt)
c946556b	181	{
b3d19c51	182	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	183	int ret;
c946556b SK	184
b3d19c51 SK	185	if (nn->cb_users[minorversion]++)
	186	return 0;
	187
c946556b SK	188	dprintk("NFS: create per-net callback data; net=%p\n", net);
	189
	190	ret = svc_bind(serv, net);
	191	if (ret < 0) {
	192	printk(KERN_WARNING "NFS: bind callback service failed\n");
	193	goto err_bind;
	194	}
	195
76566773 CL	196	ret = -EPROTONOSUPPORT;
	197	if (minorversion == 0)
	198	ret = nfs4_callback_up_net(serv, net);
	199	else if (xprt->ops->bc_up)
	200	ret = xprt->ops->bc_up(serv, net);
c946556b SK	201
	202	if (ret < 0) {
	203	printk(KERN_ERR "NFS: callback service start failed\n");
	204	goto err_socks;
	205	}
	206	return 0;
	207
	208	err_socks:
	209	svc_rpcb_cleanup(serv, net);
	210	err_bind:
98b0f80c	211	nn->cb_users[minorversion]--;
23c20ecd SK	212	dprintk("NFS: Couldn't create callback socket: err = %d; "
23c20ecd SK	213	"net = %p\n", ret, net);
c946556b SK	214	return ret;
	215	}
	216
f4b52bb0 TM	217	static struct svc_serv_ops nfs40_cb_sv_ops = {
f4b52bb0 TM	218	.svo_function = nfs4_callback_svc,
b9e13cdf	219	.svo_enqueue_xprt = svc_xprt_do_enqueue,
bb6aeba7	220	.svo_setup = svc_set_num_threads,
f4b52bb0 TM	221	.svo_module = THIS_MODULE,
	222	};
	223	#if defined(CONFIG_NFS_V4_1)
	224	static struct svc_serv_ops nfs41_cb_sv_ops = {
	225	.svo_function = nfs41_callback_svc,
	226	.svo_enqueue_xprt = svc_xprt_do_enqueue,
bb6aeba7	227	.svo_setup = svc_set_num_threads,
f4b52bb0	228	.svo_module = THIS_MODULE,
ea126e74 JL	229	};
ea126e74 JL	230
f4b52bb0 TM	231	struct svc_serv_ops *nfs4_cb_sv_ops[] = {
	232	[0] = &nfs40_cb_sv_ops,
	233	[1] = &nfs41_cb_sv_ops,
	234	};
	235	#else
	236	struct svc_serv_ops *nfs4_cb_sv_ops[] = {
	237	[0] = &nfs40_cb_sv_ops,
	238	[1] = NULL,
	239	};
	240	#endif
	241
dd018428 SK	242	static struct svc_serv *nfs_callback_create_svc(int minorversion)
	243	{
	244	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	245	struct svc_serv *serv;
f4b52bb0	246	struct svc_serv_ops *sv_ops;
dd018428 SK	247
	248	/*
	249	* Check whether we're already up and running.
	250	*/
3b01c11e	251	if (cb_info->serv) {
dd018428 SK	252	/*
	253	* Note: increase service usage, because later in case of error
	254	* svc_destroy() will be called.
	255	*/
	256	svc_get(cb_info->serv);
	257	return cb_info->serv;
	258	}
	259
f4b52bb0 TM	260	switch (minorversion) {
	261	case 0:
	262	sv_ops = nfs4_cb_sv_ops[0];
	263	break;
	264	default:
	265	sv_ops = nfs4_cb_sv_ops[1];
	266	}
	267
	268	if (sv_ops == NULL)
	269	return ERR_PTR(-ENOTSUPP);
	270
dd018428 SK	271	/*
	272	* Sanity check: if there's no task,
	273	* we should be the first user ...
	274	*/
	275	if (cb_info->users)
	276	printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
	277	cb_info->users);
	278
f4b52bb0	279	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
dd018428 SK	280	if (!serv) {
	281	printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
	282	return ERR_PTR(-ENOMEM);
	283	}
3b01c11e	284	cb_info->serv = serv;
dd018428 SK	285	/* As there is only one thread we need to over-ride the
	286	* default maximum of 80 connections
	287	*/
	288	serv->sv_maxconn = 1024;
	289	dprintk("nfs_callback_create_svc: service created\n");
	290	return serv;
	291	}
	292
71468513 BH	293	/*
	294	* Bring up the callback thread if it is not already up.
	295	*/
	296	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	297	{
dd018428	298	struct svc_serv *serv;
e82dc22d	299	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
23c20ecd	300	int ret;
c946556b	301	struct net *net = xprt->xprt_net;
71468513 BH	302
71468513 BH	303	mutex_lock(&nfs_callback_mutex);
dd018428 SK	304
	305	serv = nfs_callback_create_svc(minorversion);
	306	if (IS_ERR(serv)) {
	307	ret = PTR_ERR(serv);
	308	goto err_create;
	309	}
	310
76566773	311	ret = nfs_callback_up_net(minorversion, serv, net, xprt);
c946556b SK	312	if (ret < 0)
c946556b SK	313	goto err_net;
9793f7c8	314
8e246144 SK	315	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	316	if (ret < 0)
	317	goto err_start;
a277e33c	318
23c20ecd	319	cb_info->users++;
8e60029f JL	320	/*
8e60029f JL	321	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	322	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	323	* on both success and failure so that the refcount is 1 when the
	324	* thread exits.
	325	*/
23c20ecd	326	err_net:
3b01c11e TM	327	if (!cb_info->users)
3b01c11e TM	328	cb_info->serv = NULL;
dd018428 SK	329	svc_destroy(serv);
dd018428 SK	330	err_create:
353ab6e9	331	mutex_unlock(&nfs_callback_mutex);
1da177e4	332	return ret;
8e246144 SK	333
8e246144 SK	334	err_start:
b3d19c51	335	nfs_callback_down_net(minorversion, serv, net);
23c20ecd SK	336	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
23c20ecd SK	337	goto err_net;
1da177e4 LT	338	}
	339
	340	/*
5afc597c	341	* Kill the callback thread if it's no longer being used.
1da177e4	342	*/
c8ceb412	343	void nfs_callback_down(int minorversion, struct net *net)
1da177e4	344	{
e82dc22d	345	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
bb6aeba7	346	struct svc_serv *serv;
e82dc22d	347
353ab6e9	348	mutex_lock(&nfs_callback_mutex);
bb6aeba7 TM	349	serv = cb_info->serv;
bb6aeba7 TM	350	nfs_callback_down_net(minorversion, serv, net);
e82dc22d	351	cb_info->users--;
3b01c11e	352	if (cb_info->users == 0) {
bb6aeba7 TM	353	svc_get(serv);
	354	serv->sv_ops->svo_setup(serv, NULL, 0);
	355	svc_destroy(serv);
1dc42e04	356	dprintk("nfs_callback_down: service destroyed\n");
e82dc22d	357	cb_info->serv = NULL;
5afc597c	358	}
353ab6e9	359	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	360	}
1da177e4 LT	361
778be232 AA	362	/* Boolean check of RPC_AUTH_GSS principal */
	363	int
	364	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	365	{
03a4e1f6	366	char *p = rqstp->rq_cred.cr_principal;
945b34a7	367
778be232 AA	368	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	369	return 1;
	370
ece0de63 AA	371	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	372	if (clp->cl_minorversion != 0)
778be232	373	return 0;
945b34a7 OK	374	/*
	375	* It might just be a normal user principal, in which case
	376	* userspace won't bother to tell us the name at all.
	377	*/
	378	if (p == NULL)
778be232	379	return 0;
945b34a7	380
f11b2a1c JL	381	/*
	382	* Did we get the acceptor from userland during the SETCLIENID
	383	* negotiation?
	384	*/
	385	if (clp->cl_acceptor)
	386	return !strcmp(p, clp->cl_acceptor);
	387
	388	/*
	389	* Otherwise try to verify it using the cl_hostname. Note that this
	390	* doesn't work if a non-canonical hostname was used in the devname.
	391	*/
	392
945b34a7 OK	393	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	394
	395	if (memcmp(p, "nfs@", 4) != 0)
778be232	396	return 0;
945b34a7	397	p += 4;
4e0038b6	398	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	399	return 0;
778be232 AA	400	return 1;
945b34a7 OK	401	}
945b34a7 OK	402
778be232 AA	403	/*
	404	* pg_authenticate method for nfsv4 callback threads.
	405	*
	406	* The authflavor has been negotiated, so an incorrect flavor is a server
6f02dc88	407	* bug. Deny packets with incorrect authflavor.
778be232 AA	408	*
	409	* All other checking done after NFS decoding where the nfs_client can be
	410	* found in nfs4_callback_compound
	411	*/
1da177e4 LT	412	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	413	{
1da177e4	414	switch (rqstp->rq_authop->flavour) {
778be232 AA	415	case RPC_AUTH_NULL:
778be232 AA	416	if (rqstp->rq_proc != CB_NULL)
6f02dc88	417	return SVC_DENIED;
778be232 AA	418	break;
	419	case RPC_AUTH_GSS:
	420	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	421	if (svc_is_backchannel(rqstp))
6f02dc88	422	return SVC_DENIED;
1da177e4	423	}
778be232	424	return SVC_OK;
1da177e4 LT	425	}
	426
	427	/*
	428	* Define NFS4 callback program
	429	*/
1da177e4 LT	430	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	431	[1] = &nfs4_callback_version1,
07bccc2d	432	[4] = &nfs4_callback_version4,
1da177e4 LT	433	};
	434
	435	static struct svc_stat nfs4_callback_stats;
	436
	437	static struct svc_program nfs4_callback_program = {
	438	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	439	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	440	.pg_vers = nfs4_callback_version, /* version table */
	441	.pg_name = "NFSv4 callback", /* service name */
	442	.pg_class = "nfs", /* authentication class */
	443	.pg_stats = &nfs4_callback_stats,
	444	.pg_authenticate = nfs_callback_authenticate,
	445	};