[linux-2.6-block.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;
	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;

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;
}

/*
 * Prepare to bring up the NFSv4 callback service
 */
static struct svc_rqst *
nfs4_callback_up(struct svc_serv *serv)
{
	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
}

#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;
}

/*
 * Bring up the NFSv4.1 callback service
 */
static struct svc_rqst *
nfs41_callback_up(struct svc_serv *serv)
{
	struct svc_rqst *rqstp;

	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);
	dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
	return rqstp;
}

static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
	*rqstpp = nfs41_callback_up(serv);
	*callback_svc = nfs41_callback_svc;
}

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 void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
	*rqstpp = ERR_PTR(-ENOTSUPP);
	*callback_svc = ERR_PTR(-ENOTSUPP);
}

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)
{
	struct svc_rqst *rqstp;
	int (*callback_svc)(void *vrqstp);
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	int ret;

	nfs_callback_bc_serv(minorversion, xprt, serv);

	if (cb_info->task)
		return 0;

	switch (minorversion) {
	case 0:
		/* v4.0 callback setup */
		rqstp = nfs4_callback_up(serv);
		callback_svc = nfs4_callback_svc;
		break;
	default:
		nfs_minorversion_callback_svc_setup(serv,
				&rqstp, &callback_svc);
	}

	if (IS_ERR(rqstp))
		return PTR_ERR(rqstp);

	svc_sock_update_bufs(serv);

	cb_info->serv = serv;
	cb_info->rqst = rqstp;
	cb_info->task = kthread_create(callback_svc, cb_info->rqst,
				    "nfsv4.%u-svc", minorversion);
	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;
		return ret;
	}
	rqstp->rq_task = cb_info->task;
	wake_up_process(cb_info->task);
	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:
	dprintk("NFS: Couldn't create callback socket: err = %d; "
			"net = %p\n", ret, net);
	return ret;
}

static struct svc_serv_ops nfs_cb_sv_ops = {
	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
};

static struct svc_serv *nfs_callback_create_svc(int minorversion)
{
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	struct svc_serv *serv;

	/*
	 * Check whether we're already up and running.
	 */
	if (cb_info->task) {
		/*
		 * Note: increase service usage, because later in case of error
		 * svc_destroy() will be called.
		 */
		svc_get(cb_info->serv);
		return 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);

	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, &nfs_cb_sv_ops);
	if (!serv) {
		printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
		return ERR_PTR(-ENOMEM);
	}
	/* 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:
	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];

	mutex_lock(&nfs_callback_mutex);
	nfs_callback_down_net(minorversion, cb_info->serv, net);
	cb_info->users--;
	if (cb_info->users == 0 && cb_info->task != NULL) {
		kthread_stop(cb_info->task);
		dprintk("nfs_callback_down: service stopped\n");
		svc_exit_thread(cb_info->rqst);
		dprintk("nfs_callback_down: service destroyed\n");
		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 = 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;
5afc597c	34	struct svc_rqst *rqst;
a277e33c	35	struct task_struct *task;
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;
c946556b	52	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
bbe0a3aa	53	nn->nfs_callback_tcpport, PF_INET, net);
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;
c946556b	59	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
29dcc16a	60	nn->nfs_callback_tcpport6, PF_INET6, net);
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
a277e33c	80	while (!kthread_should_stop()) {
1da177e4 LT	81	/*
	82	* Listen for a request on the socket
	83	*/
6fb2b47f	84	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
5b444cc9	85	if (err == -EAGAIN \|\| err == -EINTR)
1da177e4	86	continue;
6fb2b47f	87	svc_process(rqstp);
1da177e4	88	}
a277e33c	89	return 0;
1da177e4 LT	90	}
	91
	92	/*
71468513	93	* Prepare to bring up the NFSv4 callback service
1da177e4	94	*/
17280175	95	static struct svc_rqst *
691c457a	96	nfs4_callback_up(struct svc_serv *serv)
1da177e4	97	{
11fd165c	98	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
71468513 BH	99	}
71468513 BH	100
a43cde94 RL	101	#if defined(CONFIG_NFS_V4_1)
	102	/*
	103	* The callback service for NFSv4.1 callbacks
	104	*/
	105	static int
	106	nfs41_callback_svc(void *vrqstp)
	107	{
	108	struct svc_rqst *rqstp = vrqstp;
	109	struct svc_serv *serv = rqstp->rq_server;
	110	struct rpc_rqst *req;
	111	int error;
	112	DEFINE_WAIT(wq);
	113
	114	set_freezable();
	115
a43cde94	116	while (!kthread_should_stop()) {
25d280aa JL	117	if (try_to_freeze())
	118	continue;
	119
5d05e54a	120	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
a43cde94 RL	121	spin_lock_bh(&serv->sv_cb_lock);
	122	if (!list_empty(&serv->sv_cb_list)) {
	123	req = list_first_entry(&serv->sv_cb_list,
	124	struct rpc_rqst, rq_bc_list);
	125	list_del(&req->rq_bc_list);
	126	spin_unlock_bh(&serv->sv_cb_lock);
6ffa30d3	127	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94 RL	128	dprintk("Invoking bc_svc_process()\n");
	129	error = bc_svc_process(serv, req, rqstp);
	130	dprintk("bc_svc_process() returned w/ error code= %d\n",
	131	error);
	132	} else {
	133	spin_unlock_bh(&serv->sv_cb_lock);
5d05e54a	134	schedule();
6ffa30d3	135	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94	136	}
5d05e54a	137	flush_signals(current);
a43cde94	138	}
a43cde94 RL	139	return 0;
	140	}
	141
	142	/*
	143	* Bring up the NFSv4.1 callback service
	144	*/
17280175	145	static struct svc_rqst *
691c457a	146	nfs41_callback_up(struct svc_serv *serv)
a43cde94	147	{
01c9a0bc	148	struct svc_rqst *rqstp;
8f975242	149
a43cde94 RL	150	INIT_LIST_HEAD(&serv->sv_cb_list);
	151	spin_lock_init(&serv->sv_cb_lock);
	152	init_waitqueue_head(&serv->sv_cb_waitq);
11fd165c	153	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
54bcfa66	154	dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
8f975242	155	return rqstp;
a43cde94 RL	156	}
a43cde94 RL	157
758201e2	158	static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
a43cde94 RL	159	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
a43cde94 RL	160	{
758201e2 TM	161	*rqstpp = nfs41_callback_up(serv);
758201e2 TM	162	*callback_svc = nfs41_callback_svc;
a43cde94 RL	163	}
	164
	165	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	166	struct svc_serv *serv)
a43cde94 RL	167	{
a43cde94 RL	168	if (minorversion)
691c457a SK	169	/*
	170	* Save the svc_serv in the transport so that it can
	171	* be referenced when the session backchannel is initialized
	172	*/
	173	xprt->bc_serv = serv;
a43cde94 RL	174	}
a43cde94 RL	175	#else
758201e2	176	static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
a43cde94 RL	177	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
a43cde94 RL	178	{
758201e2 TM	179	*rqstpp = ERR_PTR(-ENOTSUPP);
758201e2 TM	180	*callback_svc = ERR_PTR(-ENOTSUPP);
a43cde94 RL	181	}
	182
	183	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	184	struct svc_serv *serv)
a43cde94 RL	185	{
	186	}
	187	#endif /* CONFIG_NFS_V4_1 */
	188
8e246144 SK	189	static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
	190	struct svc_serv *serv)
	191	{
	192	struct svc_rqst *rqstp;
	193	int (callback_svc)(void vrqstp);
	194	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
8e246144	195	int ret;
8e246144 SK	196
	197	nfs_callback_bc_serv(minorversion, xprt, serv);
	198
23c20ecd SK	199	if (cb_info->task)
	200	return 0;
	201
758201e2 TM	202	switch (minorversion) {
758201e2 TM	203	case 0:
8e246144 SK	204	/* v4.0 callback setup */
	205	rqstp = nfs4_callback_up(serv);
	206	callback_svc = nfs4_callback_svc;
758201e2 TM	207	break;
	208	default:
	209	nfs_minorversion_callback_svc_setup(serv,
	210	&rqstp, &callback_svc);
8e246144 SK	211	}
	212
	213	if (IS_ERR(rqstp))
	214	return PTR_ERR(rqstp);
	215
	216	svc_sock_update_bufs(serv);
	217
8e246144 SK	218	cb_info->serv = serv;
8e246144 SK	219	cb_info->rqst = rqstp;
66f09ca7	220	cb_info->task = kthread_create(callback_svc, cb_info->rqst,
f170168b	221	"nfsv4.%u-svc", minorversion);
8e246144 SK	222	if (IS_ERR(cb_info->task)) {
	223	ret = PTR_ERR(cb_info->task);
	224	svc_exit_thread(cb_info->rqst);
	225	cb_info->rqst = NULL;
	226	cb_info->task = NULL;
e9b7e917	227	return ret;
8e246144	228	}
88799977	229	rqstp->rq_task = cb_info->task;
66f09ca7	230	wake_up_process(cb_info->task);
8e246144 SK	231	dprintk("nfs_callback_up: service started\n");
	232	return 0;
	233	}
	234
b3d19c51 SK	235	static void nfs_callback_down_net(u32 minorversion, struct svc_serv serv, struct net net)
	236	{
	237	struct nfs_net *nn = net_generic(net, nfs_net_id);
	238
	239	if (--nn->cb_users[minorversion])
	240	return;
	241
	242	dprintk("NFS: destroy per-net callback data; net=%p\n", net);
	243	svc_shutdown_net(serv, net);
	244	}
	245
76566773 CL	246	static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
76566773 CL	247	struct net net, struct rpc_xprt xprt)
c946556b	248	{
b3d19c51	249	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	250	int ret;
c946556b SK	251
b3d19c51 SK	252	if (nn->cb_users[minorversion]++)
	253	return 0;
	254
c946556b SK	255	dprintk("NFS: create per-net callback data; net=%p\n", net);
	256
	257	ret = svc_bind(serv, net);
	258	if (ret < 0) {
	259	printk(KERN_WARNING "NFS: bind callback service failed\n");
	260	goto err_bind;
	261	}
	262
76566773 CL	263	ret = -EPROTONOSUPPORT;
	264	if (minorversion == 0)
	265	ret = nfs4_callback_up_net(serv, net);
	266	else if (xprt->ops->bc_up)
	267	ret = xprt->ops->bc_up(serv, net);
c946556b SK	268
	269	if (ret < 0) {
	270	printk(KERN_ERR "NFS: callback service start failed\n");
	271	goto err_socks;
	272	}
	273	return 0;
	274
	275	err_socks:
	276	svc_rpcb_cleanup(serv, net);
	277	err_bind:
23c20ecd SK	278	dprintk("NFS: Couldn't create callback socket: err = %d; "
23c20ecd SK	279	"net = %p\n", ret, net);
c946556b SK	280	return ret;
	281	}
	282
ea126e74	283	static struct svc_serv_ops nfs_cb_sv_ops = {
b9e13cdf	284	.svo_enqueue_xprt = svc_xprt_do_enqueue,
ea126e74 JL	285	};
ea126e74 JL	286
dd018428 SK	287	static struct svc_serv *nfs_callback_create_svc(int minorversion)
	288	{
	289	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	290	struct svc_serv *serv;
	291
	292	/*
	293	* Check whether we're already up and running.
	294	*/
	295	if (cb_info->task) {
	296	/*
	297	* Note: increase service usage, because later in case of error
	298	* svc_destroy() will be called.
	299	*/
	300	svc_get(cb_info->serv);
	301	return cb_info->serv;
	302	}
	303
	304	/*
	305	* Sanity check: if there's no task,
	306	* we should be the first user ...
	307	*/
	308	if (cb_info->users)
	309	printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
	310	cb_info->users);
	311
ea126e74	312	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, &nfs_cb_sv_ops);
dd018428 SK	313	if (!serv) {
	314	printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
	315	return ERR_PTR(-ENOMEM);
	316	}
	317	/* As there is only one thread we need to over-ride the
	318	* default maximum of 80 connections
	319	*/
	320	serv->sv_maxconn = 1024;
	321	dprintk("nfs_callback_create_svc: service created\n");
	322	return serv;
	323	}
	324
71468513 BH	325	/*
	326	* Bring up the callback thread if it is not already up.
	327	*/
	328	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	329	{
dd018428	330	struct svc_serv *serv;
e82dc22d	331	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
23c20ecd	332	int ret;
c946556b	333	struct net *net = xprt->xprt_net;
71468513 BH	334
71468513 BH	335	mutex_lock(&nfs_callback_mutex);
dd018428 SK	336
	337	serv = nfs_callback_create_svc(minorversion);
	338	if (IS_ERR(serv)) {
	339	ret = PTR_ERR(serv);
	340	goto err_create;
	341	}
	342
76566773	343	ret = nfs_callback_up_net(minorversion, serv, net, xprt);
c946556b SK	344	if (ret < 0)
c946556b SK	345	goto err_net;
9793f7c8	346
8e246144 SK	347	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	348	if (ret < 0)
	349	goto err_start;
a277e33c	350
23c20ecd	351	cb_info->users++;
8e60029f JL	352	/*
8e60029f JL	353	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	354	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	355	* on both success and failure so that the refcount is 1 when the
	356	* thread exits.
	357	*/
23c20ecd	358	err_net:
dd018428 SK	359	svc_destroy(serv);
dd018428 SK	360	err_create:
353ab6e9	361	mutex_unlock(&nfs_callback_mutex);
1da177e4	362	return ret;
8e246144 SK	363
8e246144 SK	364	err_start:
b3d19c51	365	nfs_callback_down_net(minorversion, serv, net);
23c20ecd SK	366	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
23c20ecd SK	367	goto err_net;
1da177e4 LT	368	}
	369
	370	/*
5afc597c	371	* Kill the callback thread if it's no longer being used.
1da177e4	372	*/
c8ceb412	373	void nfs_callback_down(int minorversion, struct net *net)
1da177e4	374	{
e82dc22d AA	375	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	376
353ab6e9	377	mutex_lock(&nfs_callback_mutex);
b3d19c51	378	nfs_callback_down_net(minorversion, cb_info->serv, net);
e82dc22d AA	379	cb_info->users--;
	380	if (cb_info->users == 0 && cb_info->task != NULL) {
	381	kthread_stop(cb_info->task);
1dc42e04	382	dprintk("nfs_callback_down: service stopped\n");
e82dc22d	383	svc_exit_thread(cb_info->rqst);
1dc42e04	384	dprintk("nfs_callback_down: service destroyed\n");
e82dc22d AA	385	cb_info->serv = NULL;
	386	cb_info->rqst = NULL;
	387	cb_info->task = NULL;
5afc597c	388	}
353ab6e9	389	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	390	}
1da177e4 LT	391
778be232 AA	392	/* Boolean check of RPC_AUTH_GSS principal */
	393	int
	394	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	395	{
03a4e1f6	396	char *p = rqstp->rq_cred.cr_principal;
945b34a7	397
778be232 AA	398	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	399	return 1;
	400
ece0de63 AA	401	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	402	if (clp->cl_minorversion != 0)
778be232	403	return 0;
945b34a7 OK	404	/*
	405	* It might just be a normal user principal, in which case
	406	* userspace won't bother to tell us the name at all.
	407	*/
	408	if (p == NULL)
778be232	409	return 0;
945b34a7	410
f11b2a1c JL	411	/*
	412	* Did we get the acceptor from userland during the SETCLIENID
	413	* negotiation?
	414	*/
	415	if (clp->cl_acceptor)
	416	return !strcmp(p, clp->cl_acceptor);
	417
	418	/*
	419	* Otherwise try to verify it using the cl_hostname. Note that this
	420	* doesn't work if a non-canonical hostname was used in the devname.
	421	*/
	422
945b34a7 OK	423	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	424
	425	if (memcmp(p, "nfs@", 4) != 0)
778be232	426	return 0;
945b34a7	427	p += 4;
4e0038b6	428	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	429	return 0;
778be232 AA	430	return 1;
945b34a7 OK	431	}
945b34a7 OK	432
778be232 AA	433	/*
	434	* pg_authenticate method for nfsv4 callback threads.
	435	*
	436	* The authflavor has been negotiated, so an incorrect flavor is a server
6f02dc88	437	* bug. Deny packets with incorrect authflavor.
778be232 AA	438	*
	439	* All other checking done after NFS decoding where the nfs_client can be
	440	* found in nfs4_callback_compound
	441	*/
1da177e4 LT	442	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	443	{
1da177e4	444	switch (rqstp->rq_authop->flavour) {
778be232 AA	445	case RPC_AUTH_NULL:
778be232 AA	446	if (rqstp->rq_proc != CB_NULL)
6f02dc88	447	return SVC_DENIED;
778be232 AA	448	break;
	449	case RPC_AUTH_GSS:
	450	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	451	if (svc_is_backchannel(rqstp))
6f02dc88	452	return SVC_DENIED;
1da177e4	453	}
778be232	454	return SVC_OK;
1da177e4 LT	455	}
	456
	457	/*
	458	* Define NFS4 callback program
	459	*/
1da177e4 LT	460	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	461	[1] = &nfs4_callback_version1,
07bccc2d	462	[4] = &nfs4_callback_version4,
1da177e4 LT	463	};
	464
	465	static struct svc_stat nfs4_callback_stats;
	466
	467	static struct svc_program nfs4_callback_program = {
	468	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	469	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	470	.pg_vers = nfs4_callback_version, /* version table */
	471	.pg_name = "NFSv4 callback", /* service name */
	472	.pg_class = "nfs", /* authentication class */
	473	.pg_stats = &nfs4_callback_stats,
	474	.pg_authenticate = nfs_callback_authenticate,
	475	};