[GitHub/mt8127/android_kernel_alcatel_ttab.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/smp_lock.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>
#if defined(CONFIG_NFS_V4_1)
#include <linux/sunrpc/bc_xprt.h>
#endif

#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 int nfs_callback_set_tcpport;
unsigned short nfs_callback_tcpport;
unsigned short nfs_callback_tcpport6;
#define NFS_CALLBACK_MAXPORTNR (65535U)

static int param_set_portnr(const char *val, struct kernel_param *kp)
{
	unsigned long num;
	int ret;

	if (!val)
		return -EINVAL;
	ret = strict_strtoul(val, 0, &num);
	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
		return -EINVAL;
	*((unsigned int *)kp->arg) = num;
	return 0;
}

static int param_get_portnr(char *buffer, struct kernel_param *kp)
{
	return param_get_uint(buffer, kp);
}
#define param_check_portnr(name, p) __param_check(name, p, unsigned int);

module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);

/*
 * 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 "%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
 */
struct svc_rqst *
nfs4_callback_up(struct svc_serv *serv)
{
	int ret;

	ret = svc_create_xprt(serv, "tcp", 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", 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]);

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
 */
struct svc_rqst *
nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
{
	struct svc_xprt *bc_xprt;
	struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);

	dprintk("--> %s\n", __func__);
	/* Create a svc_sock for the service */
	bc_xprt = svc_sock_create(serv, xprt->prot);
	if (!bc_xprt)
		goto out;

	/*
	 * Save the svc_serv in the transport so that it can
	 * be referenced when the session backchannel is initialized
	 */
	serv->bc_xprt = bc_xprt;
	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]);
	if (IS_ERR(rqstp))
		svc_sock_destroy(bc_xprt);
out:
	dprintk("--> %s return %p\n", __func__, rqstp);
	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;

	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;
	}

	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);
		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--;
	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_exit_thread(cb_info->rqst);
		cb_info->serv = NULL;
		cb_info->rqst = NULL;
		cb_info->task = NULL;
	}
	mutex_unlock(&nfs_callback_mutex);
}

static int check_gss_callback_principal(struct nfs_client *clp,
					struct svc_rqst *rqstp)
{
	struct rpc_clnt *r = clp->cl_rpcclient;
	char *p = svc_gss_principal(rqstp);

	/*
	 * 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 SVC_DENIED;

	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */

	if (memcmp(p, "nfs@", 4) != 0)
		return SVC_DENIED;
	p += 4;
	if (strcmp(p, r->cl_server) != 0)
		return SVC_DENIED;
	return SVC_OK;
}

static int nfs_callback_authenticate(struct svc_rqst *rqstp)
{
	struct nfs_client *clp;
	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
	int ret = SVC_OK;

	/* Don't talk to strangers */
	clp = nfs_find_client(svc_addr(rqstp), 4);
	if (clp == NULL)
		return SVC_DROP;

	dprintk("%s: %s NFSv4 callback!\n", __func__,
			svc_print_addr(rqstp, buf, sizeof(buf)));

	switch (rqstp->rq_authop->flavour) {
		case RPC_AUTH_NULL:
			if (rqstp->rq_proc != CB_NULL)
				ret = SVC_DENIED;
			break;
		case RPC_AUTH_UNIX:
			break;
		case RPC_AUTH_GSS:
			ret = check_gss_callback_principal(clp, rqstp);
			break;
		default:
			ret = SVC_DENIED;
	}
	nfs_put_client(clp);
	return ret;
}

/*
 * 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>
	12	#include <linux/smp_lock.h>
	13	#include <linux/sunrpc/svc.h>
	14	#include <linux/sunrpc/svcsock.h>
	15	#include <linux/nfs_fs.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 RL	20	#if defined(CONFIG_NFS_V4_1)
	21	#include <linux/sunrpc/bc_xprt.h>
	22	#endif
14c85021 ACM	23
	24	#include <net/inet_sock.h>
	25
4ce79717	26	#include "nfs4_fs.h"
1da177e4	27	#include "callback.h"
24c8dbbb	28	#include "internal.h"
1da177e4 LT	29
	30	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	31
	32	struct nfs_callback_data {
	33	unsigned int users;
a43cde94	34	struct svc_serv *serv;
5afc597c	35	struct svc_rqst *rqst;
a277e33c	36	struct task_struct *task;
1da177e4 LT	37	};
1da177e4 LT	38
e82dc22d	39	static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
353ab6e9	40	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	41	static struct svc_program nfs4_callback_program;
1da177e4 LT	42
a72b4422	43	unsigned int nfs_callback_set_tcpport;
1da177e4	44	unsigned short nfs_callback_tcpport;
f738f517	45	unsigned short nfs_callback_tcpport6;
c140aa91	46	#define NFS_CALLBACK_MAXPORTNR (65535U)
7d4e2747	47
c140aa91	48	static int param_set_portnr(const char val, struct kernel_param kp)
7d4e2747	49	{
c140aa91 TM	50	unsigned long num;
	51	int ret;
	52
	53	if (!val)
	54	return -EINVAL;
	55	ret = strict_strtoul(val, 0, &num);
	56	if (ret == -EINVAL \|\| num > NFS_CALLBACK_MAXPORTNR)
7d4e2747	57	return -EINVAL;
c140aa91	58	((unsigned int )kp->arg) = num;
7d4e2747 DH	59	return 0;
	60	}
	61
c140aa91 TM	62	static int param_get_portnr(char buffer, struct kernel_param kp)
	63	{
	64	return param_get_uint(buffer, kp);
	65	}
	66	#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
	67
	68	module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1da177e4 LT	69
1da177e4 LT	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 JL	91	if (err != preverr) {
	92	printk(KERN_WARNING "%s: unexpected error "
	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	*/
71468513 BH	108	struct svc_rqst *
71468513 BH	109	nfs4_callback_up(struct svc_serv *serv)
1da177e4	110	{
71468513	111	int ret;
482fb94e	112
26298caa	113	ret = svc_create_xprt(serv, "tcp", PF_INET,
9652ada3	114	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
482fb94e	115	if (ret <= 0)
8e60029f	116	goto out_err;
482fb94e	117	nfs_callback_tcpport = ret;
18de9735	118	dprintk("NFS: Callback listener port = %u (af %u)\n",
26298caa	119	nfs_callback_tcpport, PF_INET);
482fb94e	120
f738f517 CL	121	ret = svc_create_xprt(serv, "tcp", PF_INET6,
	122	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	123	if (ret > 0) {
	124	nfs_callback_tcpport6 = ret;
	125	dprintk("NFS: Callback listener port = %u (af %u)\n",
	126	nfs_callback_tcpport6, PF_INET6);
18fc3164 CL	127	} else if (ret == -EAFNOSUPPORT)
	128	ret = 0;
	129	else
f738f517	130	goto out_err;
f738f517	131
71468513 BH	132	return svc_prepare_thread(serv, &serv->sv_pools[0]);
	133
	134	out_err:
	135	if (ret == 0)
	136	ret = -ENOMEM;
	137	return ERR_PTR(ret);
	138	}
	139
a43cde94 RL	140	#if defined(CONFIG_NFS_V4_1)
	141	/*
	142	* The callback service for NFSv4.1 callbacks
	143	*/
	144	static int
	145	nfs41_callback_svc(void *vrqstp)
	146	{
	147	struct svc_rqst *rqstp = vrqstp;
	148	struct svc_serv *serv = rqstp->rq_server;
	149	struct rpc_rqst *req;
	150	int error;
	151	DEFINE_WAIT(wq);
	152
	153	set_freezable();
	154
a43cde94 RL	155	while (!kthread_should_stop()) {
	156	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	157	spin_lock_bh(&serv->sv_cb_lock);
	158	if (!list_empty(&serv->sv_cb_list)) {
	159	req = list_first_entry(&serv->sv_cb_list,
	160	struct rpc_rqst, rq_bc_list);
	161	list_del(&req->rq_bc_list);
	162	spin_unlock_bh(&serv->sv_cb_lock);
	163	dprintk("Invoking bc_svc_process()\n");
	164	error = bc_svc_process(serv, req, rqstp);
	165	dprintk("bc_svc_process() returned w/ error code= %d\n",
	166	error);
	167	} else {
	168	spin_unlock_bh(&serv->sv_cb_lock);
	169	schedule();
	170	}
	171	finish_wait(&serv->sv_cb_waitq, &wq);
	172	}
a43cde94 RL	173	return 0;
	174	}
	175
	176	/*
	177	* Bring up the NFSv4.1 callback service
	178	*/
	179	struct svc_rqst *
	180	nfs41_callback_up(struct svc_serv serv, struct rpc_xprt xprt)
	181	{
8f975242 BH	182	struct svc_xprt *bc_xprt;
	183	struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
	184
	185	dprintk("--> %s\n", __func__);
	186	/* Create a svc_sock for the service */
	187	bc_xprt = svc_sock_create(serv, xprt->prot);
	188	if (!bc_xprt)
	189	goto out;
	190
a43cde94 RL	191	/*
	192	* Save the svc_serv in the transport so that it can
	193	* be referenced when the session backchannel is initialized
	194	*/
8f975242	195	serv->bc_xprt = bc_xprt;
a43cde94 RL	196	xprt->bc_serv = serv;
	197
	198	INIT_LIST_HEAD(&serv->sv_cb_list);
	199	spin_lock_init(&serv->sv_cb_lock);
	200	init_waitqueue_head(&serv->sv_cb_waitq);
8f975242 BH	201	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
	202	if (IS_ERR(rqstp))
	203	svc_sock_destroy(bc_xprt);
	204	out:
	205	dprintk("--> %s return %p\n", __func__, rqstp);
	206	return rqstp;
a43cde94 RL	207	}
	208
	209	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	210	struct svc_serv serv, struct rpc_xprt xprt,
	211	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	212	{
	213	if (minorversion) {
	214	*rqstpp = nfs41_callback_up(serv, xprt);
	215	*callback_svc = nfs41_callback_svc;
	216	}
	217	return minorversion;
	218	}
	219
	220	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	221	struct nfs_callback_data *cb_info)
	222	{
	223	if (minorversion)
	224	xprt->bc_serv = cb_info->serv;
	225	}
	226	#else
	227	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	228	struct svc_serv serv, struct rpc_xprt xprt,
	229	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	230	{
	231	return 0;
	232	}
	233
	234	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	235	struct nfs_callback_data *cb_info)
	236	{
	237	}
	238	#endif /* CONFIG_NFS_V4_1 */
	239
71468513 BH	240	/*
	241	* Bring up the callback thread if it is not already up.
	242	*/
	243	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	244	{
	245	struct svc_serv *serv = NULL;
	246	struct svc_rqst *rqstp;
	247	int (callback_svc)(void vrqstp);
e82dc22d	248	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
71468513 BH	249	char svc_name[12];
71468513 BH	250	int ret = 0;
a43cde94	251	int minorversion_setup;
71468513 BH	252
71468513 BH	253	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	254	if (cb_info->users++ \|\| cb_info->task != NULL) {
e82dc22d AA	255	nfs_callback_bc_serv(minorversion, xprt, cb_info);
71468513	256	goto out;
a43cde94	257	}
71468513 BH	258	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	259	if (!serv) {
	260	ret = -ENOMEM;
	261	goto out_err;
	262	}
	263
a43cde94 RL	264	minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
	265	serv, xprt, &rqstp, &callback_svc);
	266	if (!minorversion_setup) {
	267	/* v4.0 callback setup */
71468513 BH	268	rqstp = nfs4_callback_up(serv);
71468513 BH	269	callback_svc = nfs4_callback_svc;
71468513 BH	270	}
	271
	272	if (IS_ERR(rqstp)) {
	273	ret = PTR_ERR(rqstp);
8e60029f	274	goto out_err;
a277e33c JL	275	}
	276
	277	svc_sock_update_bufs(serv);
a277e33c	278
71468513	279	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
e82dc22d AA	280	cb_info->serv = serv;
	281	cb_info->rqst = rqstp;
	282	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
	283	if (IS_ERR(cb_info->task)) {
	284	ret = PTR_ERR(cb_info->task);
	285	svc_exit_thread(cb_info->rqst);
	286	cb_info->rqst = NULL;
	287	cb_info->task = NULL;
a277e33c JL	288	goto out_err;
a277e33c JL	289	}
1da177e4	290	out:
8e60029f JL	291	/*
8e60029f JL	292	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	293	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	294	* on both success and failure so that the refcount is 1 when the
	295	* thread exits.
	296	*/
	297	if (serv)
	298	svc_destroy(serv);
353ab6e9	299	mutex_unlock(&nfs_callback_mutex);
1da177e4	300	return ret;
8e60029f	301	out_err:
18de9735 CL	302	dprintk("NFS: Couldn't create callback socket or server thread; "
18de9735 CL	303	"err = %d\n", ret);
e82dc22d	304	cb_info->users--;
1da177e4 LT	305	goto out;
	306	}
	307
	308	/*
5afc597c	309	* Kill the callback thread if it's no longer being used.
1da177e4	310	*/
e82dc22d	311	void nfs_callback_down(int minorversion)
1da177e4	312	{
e82dc22d AA	313	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	314
353ab6e9	315	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	316	cb_info->users--;
	317	if (cb_info->users == 0 && cb_info->task != NULL) {
	318	kthread_stop(cb_info->task);
	319	svc_exit_thread(cb_info->rqst);
	320	cb_info->serv = NULL;
	321	cb_info->rqst = NULL;
	322	cb_info->task = NULL;
5afc597c	323	}
353ab6e9	324	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	325	}
1da177e4 LT	326
945b34a7 OK	327	static int check_gss_callback_principal(struct nfs_client *clp,
	328	struct svc_rqst *rqstp)
	329	{
	330	struct rpc_clnt *r = clp->cl_rpcclient;
	331	char *p = svc_gss_principal(rqstp);
	332
	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)
	338	return SVC_DENIED;
	339
	340	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	341
	342	if (memcmp(p, "nfs@", 4) != 0)
	343	return SVC_DENIED;
	344	p += 4;
	345	if (strcmp(p, r->cl_server) != 0)
	346	return SVC_DENIED;
	347	return SVC_OK;
	348	}
	349
1da177e4 LT	350	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	351	{
adfa6f98	352	struct nfs_client *clp;
5216a8e7	353	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
945b34a7	354	int ret = SVC_OK;
1da177e4 LT	355
1da177e4 LT	356	/* Don't talk to strangers */
ff052645	357	clp = nfs_find_client(svc_addr(rqstp), 4);
1da177e4 LT	358	if (clp == NULL)
1da177e4 LT	359	return SVC_DROP;
ad06e4bd	360
3110ff80	361	dprintk("%s: %s NFSv4 callback!\n", __func__,
ad06e4bd	362	svc_print_addr(rqstp, buf, sizeof(buf)));
ad06e4bd	363
1da177e4 LT	364	switch (rqstp->rq_authop->flavour) {
	365	case RPC_AUTH_NULL:
	366	if (rqstp->rq_proc != CB_NULL)
945b34a7	367	ret = SVC_DENIED;
1da177e4 LT	368	break;
	369	case RPC_AUTH_UNIX:
	370	break;
	371	case RPC_AUTH_GSS:
945b34a7 OK	372	ret = check_gss_callback_principal(clp, rqstp);
945b34a7 OK	373	break;
1da177e4	374	default:
945b34a7	375	ret = SVC_DENIED;
1da177e4	376	}
945b34a7 OK	377	nfs_put_client(clp);
945b34a7 OK	378	return ret;
1da177e4 LT	379	}
	380
	381	/*
	382	* Define NFS4 callback program
	383	*/
1da177e4 LT	384	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	385	[1] = &nfs4_callback_version1,
07bccc2d	386	[4] = &nfs4_callback_version4,
1da177e4 LT	387	};
	388
	389	static struct svc_stat nfs4_callback_stats;
	390
	391	static struct svc_program nfs4_callback_program = {
	392	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	393	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	394	.pg_vers = nfs4_callback_version, /* version table */
	395	.pg_name = "NFSv4 callback", /* service name */
	396	.pg_class = "nfs", /* authentication class */
	397	.pg_stats = &nfs4_callback_stats,
	398	.pg_authenticate = nfs_callback_authenticate,
	399	};