[mirror_ubuntu-artful-kernel.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;

unsigned short nfs_callback_tcpport6;

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) {
		nfs_callback_tcpport6 = ret;
		dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
				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
f738f517	41	unsigned short nfs_callback_tcpport6;
1da177e4	42
c946556b SK	43	static int nfs4_callback_up_net(struct svc_serv serv, struct net net)
	44	{
	45	int ret;
bbe0a3aa	46	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	47
	48	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
	49	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	50	if (ret <= 0)
	51	goto out_err;
bbe0a3aa	52	nn->nfs_callback_tcpport = ret;
c946556b	53	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
bbe0a3aa	54	nn->nfs_callback_tcpport, PF_INET, net);
c946556b SK	55
	56	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
	57	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	58	if (ret > 0) {
	59	nfs_callback_tcpport6 = ret;
	60	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
	61	nfs_callback_tcpport6, PF_INET6, net);
	62	} else if (ret != -EAFNOSUPPORT)
	63	goto out_err;
	64	return 0;
	65
	66	out_err:
	67	return (ret) ? ret : -ENOMEM;
	68	}
	69
1da177e4	70	/*
e82dc22d	71	* This is the NFSv4 callback kernel thread.
1da177e4	72	*/
a277e33c	73	static int
71468513	74	nfs4_callback_svc(void *vrqstp)
1da177e4	75	{
06e02d66	76	int err, preverr = 0;
a277e33c	77	struct svc_rqst *rqstp = vrqstp;
1da177e4	78
83144186	79	set_freezable();
1da177e4	80
a277e33c	81	while (!kthread_should_stop()) {
1da177e4 LT	82	/*
	83	* Listen for a request on the socket
	84	*/
6fb2b47f	85	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
06e02d66 JL	86	if (err == -EAGAIN \|\| err == -EINTR) {
06e02d66 JL	87	preverr = err;
1da177e4	88	continue;
06e02d66	89	}
1da177e4	90	if (err < 0) {
06e02d66	91	if (err != preverr) {
a030889a	92	printk(KERN_WARNING "NFS: %s: unexpected error "
06e02d66 JL	93	"from svc_recv (%d)\n", __func__, err);
	94	preverr = err;
	95	}
	96	schedule_timeout_uninterruptible(HZ);
	97	continue;
1da177e4	98	}
06e02d66	99	preverr = err;
6fb2b47f	100	svc_process(rqstp);
1da177e4	101	}
a277e33c	102	return 0;
1da177e4 LT	103	}
	104
	105	/*
71468513	106	* Prepare to bring up the NFSv4 callback service
1da177e4	107	*/
17280175	108	static struct svc_rqst *
691c457a	109	nfs4_callback_up(struct svc_serv *serv)
1da177e4	110	{
11fd165c	111	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
71468513 BH	112	}
71468513 BH	113
a43cde94	114	#if defined(CONFIG_NFS_V4_1)
c946556b SK	115	static int nfs41_callback_up_net(struct svc_serv serv, struct net net)
	116	{
	117	/*
	118	* Create an svc_sock for the back channel service that shares the
	119	* fore channel connection.
	120	* Returns the input port (0) and sets the svc_serv bc_xprt on success
	121	*/
	122	return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
	123	SVC_SOCK_ANONYMOUS);
	124	}
	125
a43cde94 RL	126	/*
	127	* The callback service for NFSv4.1 callbacks
	128	*/
	129	static int
	130	nfs41_callback_svc(void *vrqstp)
	131	{
	132	struct svc_rqst *rqstp = vrqstp;
	133	struct svc_serv *serv = rqstp->rq_server;
	134	struct rpc_rqst *req;
	135	int error;
	136	DEFINE_WAIT(wq);
	137
	138	set_freezable();
	139
a43cde94 RL	140	while (!kthread_should_stop()) {
	141	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	142	spin_lock_bh(&serv->sv_cb_lock);
	143	if (!list_empty(&serv->sv_cb_list)) {
	144	req = list_first_entry(&serv->sv_cb_list,
	145	struct rpc_rqst, rq_bc_list);
	146	list_del(&req->rq_bc_list);
	147	spin_unlock_bh(&serv->sv_cb_lock);
	148	dprintk("Invoking bc_svc_process()\n");
	149	error = bc_svc_process(serv, req, rqstp);
	150	dprintk("bc_svc_process() returned w/ error code= %d\n",
	151	error);
	152	} else {
	153	spin_unlock_bh(&serv->sv_cb_lock);
	154	schedule();
	155	}
	156	finish_wait(&serv->sv_cb_waitq, &wq);
	157	}
a43cde94 RL	158	return 0;
	159	}
	160
	161	/*
	162	* Bring up the NFSv4.1 callback service
	163	*/
17280175	164	static struct svc_rqst *
691c457a	165	nfs41_callback_up(struct svc_serv *serv)
a43cde94	166	{
01c9a0bc	167	struct svc_rqst *rqstp;
8f975242	168
a43cde94 RL	169	INIT_LIST_HEAD(&serv->sv_cb_list);
	170	spin_lock_init(&serv->sv_cb_lock);
	171	init_waitqueue_head(&serv->sv_cb_waitq);
11fd165c	172	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
01c9a0bc	173	if (IS_ERR(rqstp)) {
4a19de0f AA	174	svc_xprt_put(serv->sv_bc_xprt);
4a19de0f AA	175	serv->sv_bc_xprt = NULL;
01c9a0bc	176	}
01c9a0bc AA	177	dprintk("--> %s return %ld\n", __func__,
01c9a0bc AA	178	IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
8f975242	179	return rqstp;
a43cde94 RL	180	}
	181
	182	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
691c457a	183	struct svc_serv *serv,
a43cde94 RL	184	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	185	{
	186	if (minorversion) {
691c457a	187	*rqstpp = nfs41_callback_up(serv);
a43cde94 RL	188	*callback_svc = nfs41_callback_svc;
	189	}
	190	return minorversion;
	191	}
	192
	193	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	194	struct svc_serv *serv)
a43cde94 RL	195	{
a43cde94 RL	196	if (minorversion)
691c457a SK	197	/*
	198	* Save the svc_serv in the transport so that it can
	199	* be referenced when the session backchannel is initialized
	200	*/
	201	xprt->bc_serv = serv;
a43cde94 RL	202	}
a43cde94 RL	203	#else
c946556b SK	204	static int nfs41_callback_up_net(struct svc_serv serv, struct net net)
	205	{
	206	return 0;
	207	}
	208
a43cde94	209	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
691c457a	210	struct svc_serv *serv,
a43cde94 RL	211	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	212	{
	213	return 0;
	214	}
	215
	216	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	217	struct svc_serv *serv)
a43cde94 RL	218	{
	219	}
	220	#endif /* CONFIG_NFS_V4_1 */
	221
8e246144 SK	222	static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
	223	struct svc_serv *serv)
	224	{
	225	struct svc_rqst *rqstp;
	226	int (callback_svc)(void vrqstp);
	227	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	228	char svc_name[12];
	229	int ret;
	230	int minorversion_setup;
	231
	232	nfs_callback_bc_serv(minorversion, xprt, serv);
	233
23c20ecd SK	234	if (cb_info->task)
	235	return 0;
	236
8e246144 SK	237	minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
	238	serv, &rqstp, &callback_svc);
	239	if (!minorversion_setup) {
	240	/* v4.0 callback setup */
	241	rqstp = nfs4_callback_up(serv);
	242	callback_svc = nfs4_callback_svc;
	243	}
	244
	245	if (IS_ERR(rqstp))
	246	return PTR_ERR(rqstp);
	247
	248	svc_sock_update_bufs(serv);
	249
	250	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
	251	cb_info->serv = serv;
	252	cb_info->rqst = rqstp;
	253	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
	254	if (IS_ERR(cb_info->task)) {
	255	ret = PTR_ERR(cb_info->task);
	256	svc_exit_thread(cb_info->rqst);
	257	cb_info->rqst = NULL;
	258	cb_info->task = NULL;
	259	return PTR_ERR(cb_info->task);
	260	}
	261	dprintk("nfs_callback_up: service started\n");
	262	return 0;
	263	}
	264
c946556b SK	265	static int nfs_callback_up_net(int minorversion, struct svc_serv serv, struct net net)
	266	{
	267	int ret;
	268
	269	dprintk("NFS: create per-net callback data; net=%p\n", net);
	270
	271	ret = svc_bind(serv, net);
	272	if (ret < 0) {
	273	printk(KERN_WARNING "NFS: bind callback service failed\n");
	274	goto err_bind;
	275	}
	276
	277	switch (minorversion) {
	278	case 0:
	279	ret = nfs4_callback_up_net(serv, net);
	280	break;
	281	case 1:
	282	ret = nfs41_callback_up_net(serv, net);
	283	break;
	284	default:
	285	printk(KERN_ERR "NFS: unknown callback version: %d\n",
	286	minorversion);
	287	ret = -EINVAL;
	288	break;
	289	}
	290
	291	if (ret < 0) {
	292	printk(KERN_ERR "NFS: callback service start failed\n");
	293	goto err_socks;
	294	}
	295	return 0;
	296
	297	err_socks:
	298	svc_rpcb_cleanup(serv, net);
	299	err_bind:
23c20ecd SK	300	dprintk("NFS: Couldn't create callback socket: err = %d; "
23c20ecd SK	301	"net = %p\n", ret, net);
c946556b SK	302	return ret;
	303	}
	304
dd018428 SK	305	static struct svc_serv *nfs_callback_create_svc(int minorversion)
	306	{
	307	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	308	struct svc_serv *serv;
	309
	310	/*
	311	* Check whether we're already up and running.
	312	*/
	313	if (cb_info->task) {
	314	/*
	315	* Note: increase service usage, because later in case of error
	316	* svc_destroy() will be called.
	317	*/
	318	svc_get(cb_info->serv);
	319	return cb_info->serv;
	320	}
	321
	322	/*
	323	* Sanity check: if there's no task,
	324	* we should be the first user ...
	325	*/
	326	if (cb_info->users)
	327	printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
	328	cb_info->users);
	329
	330	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	331	if (!serv) {
	332	printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
	333	return ERR_PTR(-ENOMEM);
	334	}
	335	/* As there is only one thread we need to over-ride the
	336	* default maximum of 80 connections
	337	*/
	338	serv->sv_maxconn = 1024;
	339	dprintk("nfs_callback_create_svc: service created\n");
	340	return serv;
	341	}
	342
71468513 BH	343	/*
	344	* Bring up the callback thread if it is not already up.
	345	*/
	346	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	347	{
dd018428	348	struct svc_serv *serv;
e82dc22d	349	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
23c20ecd	350	int ret;
c946556b	351	struct net *net = xprt->xprt_net;
71468513 BH	352
71468513 BH	353	mutex_lock(&nfs_callback_mutex);
dd018428 SK	354
	355	serv = nfs_callback_create_svc(minorversion);
	356	if (IS_ERR(serv)) {
	357	ret = PTR_ERR(serv);
	358	goto err_create;
	359	}
	360
c946556b SK	361	ret = nfs_callback_up_net(minorversion, serv, net);
	362	if (ret < 0)
	363	goto err_net;
9793f7c8	364
8e246144 SK	365	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	366	if (ret < 0)
	367	goto err_start;
a277e33c	368
23c20ecd	369	cb_info->users++;
8e60029f JL	370	/*
8e60029f JL	371	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	372	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	373	* on both success and failure so that the refcount is 1 when the
	374	* thread exits.
	375	*/
23c20ecd	376	err_net:
dd018428 SK	377	svc_destroy(serv);
dd018428 SK	378	err_create:
353ab6e9	379	mutex_unlock(&nfs_callback_mutex);
1da177e4	380	return ret;
8e246144 SK	381
8e246144 SK	382	err_start:
c946556b	383	svc_shutdown_net(serv, net);
23c20ecd SK	384	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
23c20ecd SK	385	goto err_net;
1da177e4 LT	386	}
	387
	388	/*
5afc597c	389	* Kill the callback thread if it's no longer being used.
1da177e4	390	*/
c8ceb412	391	void nfs_callback_down(int minorversion, struct net *net)
1da177e4	392	{
e82dc22d AA	393	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	394
353ab6e9	395	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	396	cb_info->users--;
	397	if (cb_info->users == 0 && cb_info->task != NULL) {
	398	kthread_stop(cb_info->task);
c8ceb412	399	svc_shutdown_net(cb_info->serv, net);
e82dc22d AA	400	svc_exit_thread(cb_info->rqst);
	401	cb_info->serv = NULL;
	402	cb_info->rqst = NULL;
	403	cb_info->task = NULL;
5afc597c	404	}
353ab6e9	405	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	406	}
1da177e4 LT	407
778be232 AA	408	/* Boolean check of RPC_AUTH_GSS principal */
	409	int
	410	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	411	{
03a4e1f6	412	char *p = rqstp->rq_cred.cr_principal;
945b34a7	413
778be232 AA	414	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	415	return 1;
	416
ece0de63 AA	417	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	418	if (clp->cl_minorversion != 0)
778be232	419	return 0;
945b34a7 OK	420	/*
	421	* It might just be a normal user principal, in which case
	422	* userspace won't bother to tell us the name at all.
	423	*/
	424	if (p == NULL)
778be232	425	return 0;
945b34a7 OK	426
	427	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	428
	429	if (memcmp(p, "nfs@", 4) != 0)
778be232	430	return 0;
945b34a7	431	p += 4;
4e0038b6	432	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	433	return 0;
778be232 AA	434	return 1;
945b34a7 OK	435	}
945b34a7 OK	436
778be232 AA	437	/*
	438	* pg_authenticate method for nfsv4 callback threads.
	439	*
	440	* The authflavor has been negotiated, so an incorrect flavor is a server
	441	* bug. Drop packets with incorrect authflavor.
	442	*
	443	* All other checking done after NFS decoding where the nfs_client can be
	444	* found in nfs4_callback_compound
	445	*/
1da177e4 LT	446	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	447	{
1da177e4	448	switch (rqstp->rq_authop->flavour) {
778be232 AA	449	case RPC_AUTH_NULL:
	450	if (rqstp->rq_proc != CB_NULL)
	451	return SVC_DROP;
	452	break;
	453	case RPC_AUTH_GSS:
	454	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	455	if (svc_is_backchannel(rqstp))
	456	return SVC_DROP;
1da177e4	457	}
778be232	458	return SVC_OK;
1da177e4 LT	459	}
	460
	461	/*
	462	* Define NFS4 callback program
	463	*/
1da177e4 LT	464	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	465	[1] = &nfs4_callback_version1,
07bccc2d	466	[4] = &nfs4_callback_version4,
1da177e4 LT	467	};
	468
	469	static struct svc_stat nfs4_callback_stats;
	470
	471	static struct svc_program nfs4_callback_program = {
	472	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	473	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	474	.pg_vers = nfs4_callback_version, /* version table */
	475	.pg_name = "NFSv4 callback", /* service name */
	476	.pg_class = "nfs", /* authentication class */
	477	.pg_stats = &nfs4_callback_stats,
	478	.pg_authenticate = nfs_callback_authenticate,
	479	};