[deliverable/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/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, preverr = 0;
	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) {
			preverr = err;
			continue;
		}
		if (err < 0) {
			if (err != preverr) {
				printk(KERN_WARNING "NFS: %s: unexpected error "
					"from svc_recv (%d)\n", __func__, err);
				preverr = err;
			}
			schedule_timeout_uninterruptible(HZ);
			continue;
		}
		preverr = err;
		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)
static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
{
	/*
	 * Create an svc_sock for the back channel service that shares the
	 * fore channel connection.
	 * Returns the input port (0) and sets the svc_serv bc_xprt on success
	 */
	return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
			      SVC_SOCK_ANONYMOUS);
}

/*
 * 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()) {
		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);
			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);
	}
	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);
	if (IS_ERR(rqstp)) {
		svc_xprt_put(serv->sv_bc_xprt);
		serv->sv_bc_xprt = NULL;
	}
	dprintk("--> %s return %ld\n", __func__,
		IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
	return rqstp;
}

static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
		struct svc_serv *serv,
		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
	if (minorversion) {
		*rqstpp = nfs41_callback_up(serv);
		*callback_svc = nfs41_callback_svc;
	}
	return minorversion;
}

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 int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
{
	return 0;
}

static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
		struct svc_serv *serv,
		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
	return 0;
}

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];
	char svc_name[12];
	int ret;
	int minorversion_setup;

	nfs_callback_bc_serv(minorversion, xprt, serv);

	if (cb_info->task)
		return 0;

	minorversion_setup =  nfs_minorversion_callback_svc_setup(minorversion,
					serv, &rqstp, &callback_svc);
	if (!minorversion_setup) {
		/* v4.0 callback setup */
		rqstp = nfs4_callback_up(serv);
		callback_svc = nfs4_callback_svc;
	}

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

	svc_sock_update_bufs(serv);

	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
	cb_info->serv = serv;
	cb_info->rqst = rqstp;
	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
	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 PTR_ERR(cb_info->task);
	}
	dprintk("nfs_callback_up: service started\n");
	return 0;
}

static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
{
	int ret;

	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;
	}

	switch (minorversion) {
		case 0:
			ret = nfs4_callback_up_net(serv, net);
			break;
		case 1:
			ret = nfs41_callback_up_net(serv, net);
			break;
		default:
			printk(KERN_ERR "NFS: unknown callback version: %d\n",
					minorversion);
			ret = -EINVAL;
			break;
	}

	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 *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, NULL);
	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);
	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:
	svc_shutdown_net(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);
	cb_info->users--;
	if (cb_info->users == 0 && cb_info->task != NULL) {
		kthread_stop(cb_info->task);
		svc_shutdown_net(cb_info->serv, net);
		svc_exit_thread(cb_info->rqst);
		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;

	/* 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. Drop 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_DROP;
		break;
	case RPC_AUTH_GSS:
		/* No RPC_AUTH_GSS support yet in NFSv4.1 */
		 if (svc_is_backchannel(rqstp))
			return SVC_DROP;
	}
	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>
353ab6e9	15	#include <linux/mutex.h>
83144186	16	#include <linux/freezer.h>
a277e33c	17	#include <linux/kthread.h>
945b34a7	18	#include <linux/sunrpc/svcauth_gss.h>
a43cde94	19	#include <linux/sunrpc/bc_xprt.h>
14c85021 ACM	20
	21	#include <net/inet_sock.h>
	22
4ce79717	23	#include "nfs4_fs.h"
1da177e4	24	#include "callback.h"
24c8dbbb	25	#include "internal.h"
bbe0a3aa	26	#include "netns.h"
1da177e4 LT	27
	28	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	29
	30	struct nfs_callback_data {
	31	unsigned int users;
a43cde94	32	struct svc_serv *serv;
5afc597c	33	struct svc_rqst *rqst;
a277e33c	34	struct task_struct *task;
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)
	42	{
	43	int ret;
bbe0a3aa	44	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	45
	46	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
	47	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	48	if (ret <= 0)
	49	goto out_err;
bbe0a3aa	50	nn->nfs_callback_tcpport = ret;
c946556b	51	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
bbe0a3aa	52	nn->nfs_callback_tcpport, PF_INET, net);
c946556b SK	53
	54	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
	55	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	56	if (ret > 0) {
29dcc16a	57	nn->nfs_callback_tcpport6 = ret;
c946556b	58	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
29dcc16a	59	nn->nfs_callback_tcpport6, PF_INET6, net);
c946556b SK	60	} else if (ret != -EAFNOSUPPORT)
	61	goto out_err;
	62	return 0;
	63
	64	out_err:
	65	return (ret) ? ret : -ENOMEM;
	66	}
	67
1da177e4	68	/*
e82dc22d	69	* This is the NFSv4 callback kernel thread.
1da177e4	70	*/
a277e33c	71	static int
71468513	72	nfs4_callback_svc(void *vrqstp)
1da177e4	73	{
06e02d66	74	int err, preverr = 0;
a277e33c	75	struct svc_rqst *rqstp = vrqstp;
1da177e4	76
83144186	77	set_freezable();
1da177e4	78
a277e33c	79	while (!kthread_should_stop()) {
1da177e4 LT	80	/*
	81	* Listen for a request on the socket
	82	*/
6fb2b47f	83	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
06e02d66 JL	84	if (err == -EAGAIN \|\| err == -EINTR) {
06e02d66 JL	85	preverr = err;
1da177e4	86	continue;
06e02d66	87	}
1da177e4	88	if (err < 0) {
06e02d66	89	if (err != preverr) {
a030889a	90	printk(KERN_WARNING "NFS: %s: unexpected error "
06e02d66 JL	91	"from svc_recv (%d)\n", __func__, err);
	92	preverr = err;
	93	}
	94	schedule_timeout_uninterruptible(HZ);
	95	continue;
1da177e4	96	}
06e02d66	97	preverr = err;
6fb2b47f	98	svc_process(rqstp);
1da177e4	99	}
a277e33c	100	return 0;
1da177e4 LT	101	}
	102
	103	/*
71468513	104	* Prepare to bring up the NFSv4 callback service
1da177e4	105	*/
17280175	106	static struct svc_rqst *
691c457a	107	nfs4_callback_up(struct svc_serv *serv)
1da177e4	108	{
11fd165c	109	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
71468513 BH	110	}
71468513 BH	111
a43cde94	112	#if defined(CONFIG_NFS_V4_1)
c946556b SK	113	static int nfs41_callback_up_net(struct svc_serv serv, struct net net)
	114	{
	115	/*
	116	* Create an svc_sock for the back channel service that shares the
	117	* fore channel connection.
	118	* Returns the input port (0) and sets the svc_serv bc_xprt on success
	119	*/
	120	return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
	121	SVC_SOCK_ANONYMOUS);
	122	}
	123
a43cde94 RL	124	/*
	125	* The callback service for NFSv4.1 callbacks
	126	*/
	127	static int
	128	nfs41_callback_svc(void *vrqstp)
	129	{
	130	struct svc_rqst *rqstp = vrqstp;
	131	struct svc_serv *serv = rqstp->rq_server;
	132	struct rpc_rqst *req;
	133	int error;
	134	DEFINE_WAIT(wq);
	135
	136	set_freezable();
	137
a43cde94 RL	138	while (!kthread_should_stop()) {
	139	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	140	spin_lock_bh(&serv->sv_cb_lock);
	141	if (!list_empty(&serv->sv_cb_list)) {
	142	req = list_first_entry(&serv->sv_cb_list,
	143	struct rpc_rqst, rq_bc_list);
	144	list_del(&req->rq_bc_list);
	145	spin_unlock_bh(&serv->sv_cb_lock);
	146	dprintk("Invoking bc_svc_process()\n");
	147	error = bc_svc_process(serv, req, rqstp);
	148	dprintk("bc_svc_process() returned w/ error code= %d\n",
	149	error);
	150	} else {
	151	spin_unlock_bh(&serv->sv_cb_lock);
	152	schedule();
	153	}
	154	finish_wait(&serv->sv_cb_waitq, &wq);
	155	}
a43cde94 RL	156	return 0;
	157	}
	158
	159	/*
	160	* Bring up the NFSv4.1 callback service
	161	*/
17280175	162	static struct svc_rqst *
691c457a	163	nfs41_callback_up(struct svc_serv *serv)
a43cde94	164	{
01c9a0bc	165	struct svc_rqst *rqstp;
8f975242	166
a43cde94 RL	167	INIT_LIST_HEAD(&serv->sv_cb_list);
	168	spin_lock_init(&serv->sv_cb_lock);
	169	init_waitqueue_head(&serv->sv_cb_waitq);
11fd165c	170	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
01c9a0bc	171	if (IS_ERR(rqstp)) {
4a19de0f AA	172	svc_xprt_put(serv->sv_bc_xprt);
4a19de0f AA	173	serv->sv_bc_xprt = NULL;
01c9a0bc	174	}
01c9a0bc AA	175	dprintk("--> %s return %ld\n", __func__,
01c9a0bc AA	176	IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
8f975242	177	return rqstp;
a43cde94 RL	178	}
	179
	180	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
691c457a	181	struct svc_serv *serv,
a43cde94 RL	182	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	183	{
	184	if (minorversion) {
691c457a	185	*rqstpp = nfs41_callback_up(serv);
a43cde94 RL	186	*callback_svc = nfs41_callback_svc;
	187	}
	188	return minorversion;
	189	}
	190
	191	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	192	struct svc_serv *serv)
a43cde94 RL	193	{
a43cde94 RL	194	if (minorversion)
691c457a SK	195	/*
	196	* Save the svc_serv in the transport so that it can
	197	* be referenced when the session backchannel is initialized
	198	*/
	199	xprt->bc_serv = serv;
a43cde94 RL	200	}
a43cde94 RL	201	#else
c946556b SK	202	static int nfs41_callback_up_net(struct svc_serv serv, struct net net)
	203	{
	204	return 0;
	205	}
	206
a43cde94	207	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
691c457a	208	struct svc_serv *serv,
a43cde94 RL	209	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	210	{
	211	return 0;
	212	}
	213
	214	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	215	struct svc_serv *serv)
a43cde94 RL	216	{
	217	}
	218	#endif /* CONFIG_NFS_V4_1 */
	219
8e246144 SK	220	static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
	221	struct svc_serv *serv)
	222	{
	223	struct svc_rqst *rqstp;
	224	int (callback_svc)(void vrqstp);
	225	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	226	char svc_name[12];
	227	int ret;
	228	int minorversion_setup;
	229
	230	nfs_callback_bc_serv(minorversion, xprt, serv);
	231
23c20ecd SK	232	if (cb_info->task)
	233	return 0;
	234
8e246144 SK	235	minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
	236	serv, &rqstp, &callback_svc);
	237	if (!minorversion_setup) {
	238	/* v4.0 callback setup */
	239	rqstp = nfs4_callback_up(serv);
	240	callback_svc = nfs4_callback_svc;
	241	}
	242
	243	if (IS_ERR(rqstp))
	244	return PTR_ERR(rqstp);
	245
	246	svc_sock_update_bufs(serv);
	247
	248	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
	249	cb_info->serv = serv;
	250	cb_info->rqst = rqstp;
	251	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
	252	if (IS_ERR(cb_info->task)) {
	253	ret = PTR_ERR(cb_info->task);
	254	svc_exit_thread(cb_info->rqst);
	255	cb_info->rqst = NULL;
	256	cb_info->task = NULL;
	257	return PTR_ERR(cb_info->task);
	258	}
	259	dprintk("nfs_callback_up: service started\n");
	260	return 0;
	261	}
	262
c946556b SK	263	static int nfs_callback_up_net(int minorversion, struct svc_serv serv, struct net net)
	264	{
	265	int ret;
	266
	267	dprintk("NFS: create per-net callback data; net=%p\n", net);
	268
	269	ret = svc_bind(serv, net);
	270	if (ret < 0) {
	271	printk(KERN_WARNING "NFS: bind callback service failed\n");
	272	goto err_bind;
	273	}
	274
	275	switch (minorversion) {
	276	case 0:
	277	ret = nfs4_callback_up_net(serv, net);
	278	break;
	279	case 1:
	280	ret = nfs41_callback_up_net(serv, net);
	281	break;
	282	default:
	283	printk(KERN_ERR "NFS: unknown callback version: %d\n",
	284	minorversion);
	285	ret = -EINVAL;
	286	break;
	287	}
	288
	289	if (ret < 0) {
	290	printk(KERN_ERR "NFS: callback service start failed\n");
	291	goto err_socks;
	292	}
	293	return 0;
	294
	295	err_socks:
	296	svc_rpcb_cleanup(serv, net);
	297	err_bind:
23c20ecd SK	298	dprintk("NFS: Couldn't create callback socket: err = %d; "
23c20ecd SK	299	"net = %p\n", ret, net);
c946556b SK	300	return ret;
	301	}
	302
dd018428 SK	303	static struct svc_serv *nfs_callback_create_svc(int minorversion)
	304	{
	305	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	306	struct svc_serv *serv;
	307
	308	/*
	309	* Check whether we're already up and running.
	310	*/
	311	if (cb_info->task) {
	312	/*
	313	* Note: increase service usage, because later in case of error
	314	* svc_destroy() will be called.
	315	*/
	316	svc_get(cb_info->serv);
	317	return cb_info->serv;
	318	}
	319
	320	/*
	321	* Sanity check: if there's no task,
	322	* we should be the first user ...
	323	*/
	324	if (cb_info->users)
	325	printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
	326	cb_info->users);
	327
	328	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	329	if (!serv) {
	330	printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
	331	return ERR_PTR(-ENOMEM);
	332	}
	333	/* As there is only one thread we need to over-ride the
	334	* default maximum of 80 connections
	335	*/
	336	serv->sv_maxconn = 1024;
	337	dprintk("nfs_callback_create_svc: service created\n");
	338	return serv;
	339	}
	340
71468513 BH	341	/*
	342	* Bring up the callback thread if it is not already up.
	343	*/
	344	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	345	{
dd018428	346	struct svc_serv *serv;
e82dc22d	347	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
23c20ecd	348	int ret;
c946556b	349	struct net *net = xprt->xprt_net;
71468513 BH	350
71468513 BH	351	mutex_lock(&nfs_callback_mutex);
dd018428 SK	352
	353	serv = nfs_callback_create_svc(minorversion);
	354	if (IS_ERR(serv)) {
	355	ret = PTR_ERR(serv);
	356	goto err_create;
	357	}
	358
c946556b SK	359	ret = nfs_callback_up_net(minorversion, serv, net);
	360	if (ret < 0)
	361	goto err_net;
9793f7c8	362
8e246144 SK	363	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	364	if (ret < 0)
	365	goto err_start;
a277e33c	366
23c20ecd	367	cb_info->users++;
8e60029f JL	368	/*
8e60029f JL	369	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	370	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	371	* on both success and failure so that the refcount is 1 when the
	372	* thread exits.
	373	*/
23c20ecd	374	err_net:
dd018428 SK	375	svc_destroy(serv);
dd018428 SK	376	err_create:
353ab6e9	377	mutex_unlock(&nfs_callback_mutex);
1da177e4	378	return ret;
8e246144 SK	379
8e246144 SK	380	err_start:
c946556b	381	svc_shutdown_net(serv, net);
23c20ecd SK	382	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
23c20ecd SK	383	goto err_net;
1da177e4 LT	384	}
	385
	386	/*
5afc597c	387	* Kill the callback thread if it's no longer being used.
1da177e4	388	*/
c8ceb412	389	void nfs_callback_down(int minorversion, struct net *net)
1da177e4	390	{
e82dc22d AA	391	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	392
353ab6e9	393	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	394	cb_info->users--;
	395	if (cb_info->users == 0 && cb_info->task != NULL) {
	396	kthread_stop(cb_info->task);
c8ceb412	397	svc_shutdown_net(cb_info->serv, net);
e82dc22d AA	398	svc_exit_thread(cb_info->rqst);
	399	cb_info->serv = NULL;
	400	cb_info->rqst = NULL;
	401	cb_info->task = NULL;
5afc597c	402	}
353ab6e9	403	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	404	}
1da177e4 LT	405
778be232 AA	406	/* Boolean check of RPC_AUTH_GSS principal */
	407	int
	408	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	409	{
03a4e1f6	410	char *p = rqstp->rq_cred.cr_principal;
945b34a7	411
778be232 AA	412	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	413	return 1;
	414
ece0de63 AA	415	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	416	if (clp->cl_minorversion != 0)
778be232	417	return 0;
945b34a7 OK	418	/*
	419	* It might just be a normal user principal, in which case
	420	* userspace won't bother to tell us the name at all.
	421	*/
	422	if (p == NULL)
778be232	423	return 0;
945b34a7 OK	424
	425	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	426
	427	if (memcmp(p, "nfs@", 4) != 0)
778be232	428	return 0;
945b34a7	429	p += 4;
4e0038b6	430	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	431	return 0;
778be232 AA	432	return 1;
945b34a7 OK	433	}
945b34a7 OK	434
778be232 AA	435	/*
	436	* pg_authenticate method for nfsv4 callback threads.
	437	*
	438	* The authflavor has been negotiated, so an incorrect flavor is a server
	439	* bug. Drop packets with incorrect authflavor.
	440	*
	441	* All other checking done after NFS decoding where the nfs_client can be
	442	* found in nfs4_callback_compound
	443	*/
1da177e4 LT	444	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	445	{
1da177e4	446	switch (rqstp->rq_authop->flavour) {
778be232 AA	447	case RPC_AUTH_NULL:
	448	if (rqstp->rq_proc != CB_NULL)
	449	return SVC_DROP;
	450	break;
	451	case RPC_AUTH_GSS:
	452	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	453	if (svc_is_backchannel(rqstp))
	454	return SVC_DROP;
1da177e4	455	}
778be232	456	return SVC_OK;
1da177e4 LT	457	}
	458
	459	/*
	460	* Define NFS4 callback program
	461	*/
1da177e4 LT	462	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	463	[1] = &nfs4_callback_version1,
07bccc2d	464	[4] = &nfs4_callback_version4,
1da177e4 LT	465	};
	466
	467	static struct svc_stat nfs4_callback_stats;
	468
	469	static struct svc_program nfs4_callback_program = {
	470	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	471	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	472	.pg_vers = nfs4_callback_version, /* version table */
	473	.pg_name = "NFSv4 callback", /* service name */
	474	.pg_class = "nfs", /* authentication class */
	475	.pg_stats = &nfs4_callback_stats,
	476	.pg_authenticate = nfs_callback_authenticate,
	477	};