[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"

#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;

/*
 * 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, struct rpc_xprt *xprt)
{
	int ret;

	ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET,
				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	if (ret <= 0)
		goto out_err;
	nfs_callback_tcpport = ret;
	dprintk("NFS: Callback listener port = %u (af %u)\n",
			nfs_callback_tcpport, PF_INET);

	ret = svc_create_xprt(serv, "tcp", &init_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)\n",
				nfs_callback_tcpport6, PF_INET6);
	} else if (ret == -EAFNOSUPPORT)
		ret = 0;
	else
		goto out_err;

	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);

out_err:
	if (ret == 0)
		ret = -ENOMEM;
	return ERR_PTR(ret);
}

#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()) {
		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 rpc_xprt *xprt)
{
	struct svc_rqst *rqstp;
	int ret;

	/*
	 * 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
	 */
	ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0,
			      SVC_SOCK_ANONYMOUS);
	if (ret < 0) {
		rqstp = ERR_PTR(ret);
		goto out;
	}

	/*
	 * Save the svc_serv in the transport so that it can
	 * be referenced when the session backchannel is initialized
	 */
	xprt->bc_serv = serv;

	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;
	}
out:
	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 rpc_xprt *xprt,
		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
	if (minorversion) {
		*rqstpp = nfs41_callback_up(serv, xprt);
		*callback_svc = nfs41_callback_svc;
	}
	return minorversion;
}

static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
		struct nfs_callback_data *cb_info)
{
	if (minorversion)
		xprt->bc_serv = cb_info->serv;
}
#else
static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
		struct svc_serv *serv, struct rpc_xprt *xprt,
		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 nfs_callback_data *cb_info)
{
}
#endif /* CONFIG_NFS_V4_1 */

/*
 * 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 = NULL;
	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 = 0;
	int minorversion_setup;
	struct net *net = &init_net;

	mutex_lock(&nfs_callback_mutex);
	if (cb_info->users++ || cb_info->task != NULL) {
		nfs_callback_bc_serv(minorversion, xprt, cb_info);
		goto out;
	}
	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	if (!serv) {
		ret = -ENOMEM;
		goto out_err;
	}
	/* As there is only one thread we need to over-ride the
	 * default maximum of 80 connections
	 */
	serv->sv_maxconn = 1024;

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

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

	if (IS_ERR(rqstp)) {
		ret = PTR_ERR(rqstp);
		goto out_err;
	}

	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;
		goto out_err;
	}
out:
	/*
	 * 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.
	 */
	if (serv)
		svc_destroy(serv);
	mutex_unlock(&nfs_callback_mutex);
	return ret;
out_err:
	dprintk("NFS: Couldn't create callback socket or server thread; "
		"err = %d\n", ret);
	cb_info->users--;
	if (serv)
		svc_shutdown_net(serv, net);
	goto out;
}

/*
 * Kill the callback thread if it's no longer being used.
 */
void nfs_callback_down(int minorversion)
{
	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, &init_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"
1da177e4 LT	26
	27	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	28
	29	struct nfs_callback_data {
	30	unsigned int users;
a43cde94	31	struct svc_serv *serv;
5afc597c	32	struct svc_rqst *rqst;
a277e33c	33	struct task_struct *task;
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
f738f517	40	unsigned short nfs_callback_tcpport6;
1da177e4 LT	41
1da177e4 LT	42	/*
e82dc22d	43	* This is the NFSv4 callback kernel thread.
1da177e4	44	*/
a277e33c	45	static int
71468513	46	nfs4_callback_svc(void *vrqstp)
1da177e4	47	{
06e02d66	48	int err, preverr = 0;
a277e33c	49	struct svc_rqst *rqstp = vrqstp;
1da177e4	50
83144186	51	set_freezable();
1da177e4	52
a277e33c	53	while (!kthread_should_stop()) {
1da177e4 LT	54	/*
	55	* Listen for a request on the socket
	56	*/
6fb2b47f	57	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
06e02d66 JL	58	if (err == -EAGAIN \|\| err == -EINTR) {
06e02d66 JL	59	preverr = err;
1da177e4	60	continue;
06e02d66	61	}
1da177e4	62	if (err < 0) {
06e02d66	63	if (err != preverr) {
a030889a	64	printk(KERN_WARNING "NFS: %s: unexpected error "
06e02d66 JL	65	"from svc_recv (%d)\n", __func__, err);
	66	preverr = err;
	67	}
	68	schedule_timeout_uninterruptible(HZ);
	69	continue;
1da177e4	70	}
06e02d66	71	preverr = err;
6fb2b47f	72	svc_process(rqstp);
1da177e4	73	}
a277e33c	74	return 0;
1da177e4 LT	75	}
	76
	77	/*
71468513	78	* Prepare to bring up the NFSv4 callback service
1da177e4	79	*/
17280175	80	static struct svc_rqst *
7bb782c6	81	nfs4_callback_up(struct svc_serv serv, struct rpc_xprt xprt)
1da177e4	82	{
71468513	83	int ret;
482fb94e	84
12918b10	85	ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET,
9652ada3	86	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
482fb94e	87	if (ret <= 0)
8e60029f	88	goto out_err;
482fb94e	89	nfs_callback_tcpport = ret;
18de9735	90	dprintk("NFS: Callback listener port = %u (af %u)\n",
26298caa	91	nfs_callback_tcpport, PF_INET);
482fb94e	92
12918b10	93	ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET6,
f738f517 CL	94	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	95	if (ret > 0) {
	96	nfs_callback_tcpport6 = ret;
	97	dprintk("NFS: Callback listener port = %u (af %u)\n",
	98	nfs_callback_tcpport6, PF_INET6);
18fc3164 CL	99	} else if (ret == -EAFNOSUPPORT)
	100	ret = 0;
	101	else
f738f517	102	goto out_err;
f738f517	103
11fd165c	104	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
71468513 BH	105
	106	out_err:
	107	if (ret == 0)
	108	ret = -ENOMEM;
	109	return ERR_PTR(ret);
	110	}
	111
a43cde94 RL	112	#if defined(CONFIG_NFS_V4_1)
	113	/*
	114	* The callback service for NFSv4.1 callbacks
	115	*/
	116	static int
	117	nfs41_callback_svc(void *vrqstp)
	118	{
	119	struct svc_rqst *rqstp = vrqstp;
	120	struct svc_serv *serv = rqstp->rq_server;
	121	struct rpc_rqst *req;
	122	int error;
	123	DEFINE_WAIT(wq);
	124
	125	set_freezable();
	126
a43cde94 RL	127	while (!kthread_should_stop()) {
	128	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	129	spin_lock_bh(&serv->sv_cb_lock);
	130	if (!list_empty(&serv->sv_cb_list)) {
	131	req = list_first_entry(&serv->sv_cb_list,
	132	struct rpc_rqst, rq_bc_list);
	133	list_del(&req->rq_bc_list);
	134	spin_unlock_bh(&serv->sv_cb_lock);
	135	dprintk("Invoking bc_svc_process()\n");
	136	error = bc_svc_process(serv, req, rqstp);
	137	dprintk("bc_svc_process() returned w/ error code= %d\n",
	138	error);
	139	} else {
	140	spin_unlock_bh(&serv->sv_cb_lock);
	141	schedule();
	142	}
	143	finish_wait(&serv->sv_cb_waitq, &wq);
	144	}
a43cde94 RL	145	return 0;
	146	}
	147
	148	/*
	149	* Bring up the NFSv4.1 callback service
	150	*/
17280175	151	static struct svc_rqst *
a43cde94 RL	152	nfs41_callback_up(struct svc_serv serv, struct rpc_xprt xprt)
a43cde94 RL	153	{
01c9a0bc AA	154	struct svc_rqst *rqstp;
01c9a0bc AA	155	int ret;
8f975242	156
01c9a0bc AA	157	/*
	158	* Create an svc_sock for the back channel service that shares the
	159	* fore channel connection.
	160	* Returns the input port (0) and sets the svc_serv bc_xprt on success
	161	*/
12918b10	162	ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0,
01c9a0bc AA	163	SVC_SOCK_ANONYMOUS);
	164	if (ret < 0) {
	165	rqstp = ERR_PTR(ret);
8f975242	166	goto out;
01c9a0bc	167	}
8f975242	168
a43cde94 RL	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;
	174
	175	INIT_LIST_HEAD(&serv->sv_cb_list);
	176	spin_lock_init(&serv->sv_cb_lock);
	177	init_waitqueue_head(&serv->sv_cb_waitq);
11fd165c	178	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
01c9a0bc	179	if (IS_ERR(rqstp)) {
4a19de0f AA	180	svc_xprt_put(serv->sv_bc_xprt);
4a19de0f AA	181	serv->sv_bc_xprt = NULL;
01c9a0bc	182	}
8f975242	183	out:
01c9a0bc AA	184	dprintk("--> %s return %ld\n", __func__,
01c9a0bc AA	185	IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
8f975242	186	return rqstp;
a43cde94 RL	187	}
	188
	189	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	190	struct svc_serv serv, struct rpc_xprt xprt,
	191	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	192	{
	193	if (minorversion) {
	194	*rqstpp = nfs41_callback_up(serv, xprt);
	195	*callback_svc = nfs41_callback_svc;
	196	}
	197	return minorversion;
	198	}
	199
	200	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	201	struct nfs_callback_data *cb_info)
	202	{
	203	if (minorversion)
	204	xprt->bc_serv = cb_info->serv;
	205	}
	206	#else
	207	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	208	struct svc_serv serv, struct rpc_xprt xprt,
	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,
	215	struct nfs_callback_data *cb_info)
	216	{
	217	}
	218	#endif /* CONFIG_NFS_V4_1 */
	219
71468513 BH	220	/*
	221	* Bring up the callback thread if it is not already up.
	222	*/
	223	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	224	{
	225	struct svc_serv *serv = NULL;
	226	struct svc_rqst *rqstp;
	227	int (callback_svc)(void vrqstp);
e82dc22d	228	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
71468513 BH	229	char svc_name[12];
71468513 BH	230	int ret = 0;
a43cde94	231	int minorversion_setup;
12918b10	232	struct net *net = &init_net;
71468513 BH	233
71468513 BH	234	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	235	if (cb_info->users++ \|\| cb_info->task != NULL) {
e82dc22d AA	236	nfs_callback_bc_serv(minorversion, xprt, cb_info);
71468513	237	goto out;
a43cde94	238	}
71468513 BH	239	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	240	if (!serv) {
	241	ret = -ENOMEM;
	242	goto out_err;
	243	}
b042414f N	244	/* As there is only one thread we need to over-ride the
	245	* default maximum of 80 connections
	246	*/
	247	serv->sv_maxconn = 1024;
71468513	248
9793f7c8 SK	249	ret = svc_bind(serv, net);
	250	if (ret < 0) {
	251	printk(KERN_WARNING "NFS: bind callback service failed\n");
	252	goto out_err;
	253	}
	254
a43cde94 RL	255	minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
	256	serv, xprt, &rqstp, &callback_svc);
	257	if (!minorversion_setup) {
	258	/* v4.0 callback setup */
7bb782c6	259	rqstp = nfs4_callback_up(serv, xprt);
71468513	260	callback_svc = nfs4_callback_svc;
71468513 BH	261	}
	262
	263	if (IS_ERR(rqstp)) {
	264	ret = PTR_ERR(rqstp);
8e60029f	265	goto out_err;
a277e33c JL	266	}
	267
	268	svc_sock_update_bufs(serv);
a277e33c	269
71468513	270	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
e82dc22d AA	271	cb_info->serv = serv;
	272	cb_info->rqst = rqstp;
	273	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
	274	if (IS_ERR(cb_info->task)) {
	275	ret = PTR_ERR(cb_info->task);
	276	svc_exit_thread(cb_info->rqst);
	277	cb_info->rqst = NULL;
	278	cb_info->task = NULL;
a277e33c JL	279	goto out_err;
a277e33c JL	280	}
1da177e4	281	out:
8e60029f JL	282	/*
8e60029f JL	283	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	284	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	285	* on both success and failure so that the refcount is 1 when the
	286	* thread exits.
	287	*/
	288	if (serv)
	289	svc_destroy(serv);
353ab6e9	290	mutex_unlock(&nfs_callback_mutex);
1da177e4	291	return ret;
8e60029f	292	out_err:
18de9735 CL	293	dprintk("NFS: Couldn't create callback socket or server thread; "
18de9735 CL	294	"err = %d\n", ret);
e82dc22d	295	cb_info->users--;
786185b5 SK	296	if (serv)
786185b5 SK	297	svc_shutdown_net(serv, net);
1da177e4 LT	298	goto out;
	299	}
	300
	301	/*
5afc597c	302	* Kill the callback thread if it's no longer being used.
1da177e4	303	*/
e82dc22d	304	void nfs_callback_down(int minorversion)
1da177e4	305	{
e82dc22d AA	306	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	307
353ab6e9	308	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	309	cb_info->users--;
	310	if (cb_info->users == 0 && cb_info->task != NULL) {
	311	kthread_stop(cb_info->task);
12918b10	312	svc_shutdown_net(cb_info->serv, &init_net);
e82dc22d AA	313	svc_exit_thread(cb_info->rqst);
	314	cb_info->serv = NULL;
	315	cb_info->rqst = NULL;
	316	cb_info->task = NULL;
5afc597c	317	}
353ab6e9	318	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	319	}
1da177e4 LT	320
778be232 AA	321	/* Boolean check of RPC_AUTH_GSS principal */
	322	int
	323	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	324	{
03a4e1f6	325	char *p = rqstp->rq_cred.cr_principal;
945b34a7	326
778be232 AA	327	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	328	return 1;
	329
ece0de63 AA	330	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	331	if (clp->cl_minorversion != 0)
778be232	332	return 0;
945b34a7 OK	333	/*
	334	* It might just be a normal user principal, in which case
	335	* userspace won't bother to tell us the name at all.
	336	*/
	337	if (p == NULL)
778be232	338	return 0;
945b34a7 OK	339
	340	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	341
	342	if (memcmp(p, "nfs@", 4) != 0)
778be232	343	return 0;
945b34a7	344	p += 4;
4e0038b6	345	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	346	return 0;
778be232 AA	347	return 1;
945b34a7 OK	348	}
945b34a7 OK	349
778be232 AA	350	/*
	351	* pg_authenticate method for nfsv4 callback threads.
	352	*
	353	* The authflavor has been negotiated, so an incorrect flavor is a server
	354	* bug. Drop packets with incorrect authflavor.
	355	*
	356	* All other checking done after NFS decoding where the nfs_client can be
	357	* found in nfs4_callback_compound
	358	*/
1da177e4 LT	359	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	360	{
1da177e4	361	switch (rqstp->rq_authop->flavour) {
778be232 AA	362	case RPC_AUTH_NULL:
	363	if (rqstp->rq_proc != CB_NULL)
	364	return SVC_DROP;
	365	break;
	366	case RPC_AUTH_GSS:
	367	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	368	if (svc_is_backchannel(rqstp))
	369	return SVC_DROP;
1da177e4	370	}
778be232	371	return SVC_OK;
1da177e4 LT	372	}
	373
	374	/*
	375	* Define NFS4 callback program
	376	*/
1da177e4 LT	377	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	378	[1] = &nfs4_callback_version1,
07bccc2d	379	[4] = &nfs4_callback_version4,
1da177e4 LT	380	};
	381
	382	static struct svc_stat nfs4_callback_stats;
	383
	384	static struct svc_program nfs4_callback_program = {
	385	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	386	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	387	.pg_vers = nfs4_callback_version, /* version table */
	388	.pg_name = "NFSv4 callback", /* service name */
	389	.pg_class = "nfs", /* authentication class */
	390	.pg_stats = &nfs4_callback_stats,
	391	.pg_authenticate = nfs_callback_authenticate,
	392	};