[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;
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;
static const int nfs_set_port_min = 0;
static const int nfs_set_port_max = 65535;

static int param_set_port(const char *val, struct kernel_param *kp)
{
	char *endp;
	int num = simple_strtol(val, &endp, 0);
	if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
		return -EINVAL;
	*((int *)kp->arg) = num;
	return 0;
}

module_param_call(callback_tcpport, param_set_port, param_get_int,
		 &nfs_callback_set_tcpport, 0644);

/*
 * This is the callback kernel thread.
 */
static int
nfs4_callback_svc(void *vrqstp)
{
	int err, preverr = 0;
	struct svc_rqst *rqstp = vrqstp;

	set_freezable();

	/*
	 * FIXME: do we really need to run this under the BKL? If so, please
	 * add a comment about what it's intended to protect.
	 */
	lock_kernel();
	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);
	}
	unlock_kernel();
	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);

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	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)
		goto out_err;
#endif	/* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */

	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();

	/*
	 * FIXME: do we really need to run this under the BKL? If so, please
	 * add a comment about what it's intended to protect.
	 */
	lock_kernel();
	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);
	}
	unlock_kernel();
	nfs_callback_info.task = NULL;
	svc_exit_thread(rqstp);
	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);
	char svc_name[12];
	int ret = 0;
	int minorversion_setup;

	mutex_lock(&nfs_callback_mutex);
	if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) {
		nfs_callback_bc_serv(minorversion, xprt, &nfs_callback_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);
	nfs_callback_info.serv = serv;
	nfs_callback_info.rqst = rqstp;
	nfs_callback_info.task = kthread_run(callback_svc,
					     nfs_callback_info.rqst,
					     svc_name);
	if (IS_ERR(nfs_callback_info.task)) {
		ret = PTR_ERR(nfs_callback_info.task);
		svc_exit_thread(nfs_callback_info.rqst);
		nfs_callback_info.serv = NULL;
		nfs_callback_info.rqst = NULL;
		nfs_callback_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);
	nfs_callback_info.users--;
	goto out;
}

/*
 * Kill the callback thread if it's no longer being used.
 */
void nfs_callback_down(void)
{
	mutex_lock(&nfs_callback_mutex);
	nfs_callback_info.users--;
	if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) {
		kthread_stop(nfs_callback_info.task);
		svc_exit_thread(nfs_callback_info.rqst);
		nfs_callback_info.serv = NULL;
		nfs_callback_info.rqst = NULL;
		nfs_callback_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,
};

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	};
	38
	39	static struct nfs_callback_data nfs_callback_info;
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;
7d4e2747 DH	46	static const int nfs_set_port_min = 0;
	47	static const int nfs_set_port_max = 65535;
	48
	49	static int param_set_port(const char val, struct kernel_param kp)
	50	{
	51	char *endp;
	52	int num = simple_strtol(val, &endp, 0);
	53	if (endp == val \|\| *endp \|\| num < nfs_set_port_min \|\| num > nfs_set_port_max)
	54	return -EINVAL;
	55	((int )kp->arg) = num;
	56	return 0;
	57	}
	58
	59	module_param_call(callback_tcpport, param_set_port, param_get_int,
	60	&nfs_callback_set_tcpport, 0644);
1da177e4 LT	61
	62	/*
	63	* This is the callback kernel thread.
	64	*/
a277e33c	65	static int
71468513	66	nfs4_callback_svc(void *vrqstp)
1da177e4	67	{
06e02d66	68	int err, preverr = 0;
a277e33c	69	struct svc_rqst *rqstp = vrqstp;
1da177e4	70
83144186	71	set_freezable();
1da177e4	72
a277e33c JL	73	/*
	74	* FIXME: do we really need to run this under the BKL? If so, please
	75	* add a comment about what it's intended to protect.
	76	*/
	77	lock_kernel();
	78	while (!kthread_should_stop()) {
1da177e4 LT	79	/*
	80	* Listen for a request on the socket
	81	*/
6fb2b47f	82	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
06e02d66 JL	83	if (err == -EAGAIN \|\| err == -EINTR) {
06e02d66 JL	84	preverr = err;
1da177e4	85	continue;
06e02d66	86	}
1da177e4	87	if (err < 0) {
06e02d66 JL	88	if (err != preverr) {
	89	printk(KERN_WARNING "%s: unexpected error "
	90	"from svc_recv (%d)\n", __func__, err);
	91	preverr = err;
	92	}
	93	schedule_timeout_uninterruptible(HZ);
	94	continue;
1da177e4	95	}
06e02d66	96	preverr = err;
6fb2b47f	97	svc_process(rqstp);
1da177e4	98	}
1da177e4	99	unlock_kernel();
a277e33c	100	return 0;
1da177e4 LT	101	}
	102
	103	/*
71468513	104	* Prepare to bring up the NFSv4 callback service
1da177e4	105	*/
71468513 BH	106	struct svc_rqst *
71468513 BH	107	nfs4_callback_up(struct svc_serv *serv)
1da177e4	108	{
71468513	109	int ret;
482fb94e	110
26298caa	111	ret = svc_create_xprt(serv, "tcp", PF_INET,
9652ada3	112	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
482fb94e	113	if (ret <= 0)
8e60029f	114	goto out_err;
482fb94e	115	nfs_callback_tcpport = ret;
18de9735	116	dprintk("NFS: Callback listener port = %u (af %u)\n",
26298caa	117	nfs_callback_tcpport, PF_INET);
482fb94e	118
f738f517 CL	119	#if defined(CONFIG_IPV6) \|\| defined(CONFIG_IPV6_MODULE)
	120	ret = svc_create_xprt(serv, "tcp", PF_INET6,
	121	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	122	if (ret > 0) {
	123	nfs_callback_tcpport6 = ret;
	124	dprintk("NFS: Callback listener port = %u (af %u)\n",
	125	nfs_callback_tcpport6, PF_INET6);
	126	} else if (ret != -EAFNOSUPPORT)
	127	goto out_err;
	128	#endif /* defined(CONFIG_IPV6) \|\| defined(CONFIG_IPV6_MODULE) */
	129
71468513 BH	130	return svc_prepare_thread(serv, &serv->sv_pools[0]);
	131
	132	out_err:
	133	if (ret == 0)
	134	ret = -ENOMEM;
	135	return ERR_PTR(ret);
	136	}
	137
a43cde94 RL	138	#if defined(CONFIG_NFS_V4_1)
	139	/*
	140	* The callback service for NFSv4.1 callbacks
	141	*/
	142	static int
	143	nfs41_callback_svc(void *vrqstp)
	144	{
	145	struct svc_rqst *rqstp = vrqstp;
	146	struct svc_serv *serv = rqstp->rq_server;
	147	struct rpc_rqst *req;
	148	int error;
	149	DEFINE_WAIT(wq);
	150
	151	set_freezable();
	152
	153	/*
	154	* FIXME: do we really need to run this under the BKL? If so, please
	155	* add a comment about what it's intended to protect.
	156	*/
	157	lock_kernel();
	158	while (!kthread_should_stop()) {
	159	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	160	spin_lock_bh(&serv->sv_cb_lock);
	161	if (!list_empty(&serv->sv_cb_list)) {
	162	req = list_first_entry(&serv->sv_cb_list,
	163	struct rpc_rqst, rq_bc_list);
	164	list_del(&req->rq_bc_list);
	165	spin_unlock_bh(&serv->sv_cb_lock);
	166	dprintk("Invoking bc_svc_process()\n");
	167	error = bc_svc_process(serv, req, rqstp);
	168	dprintk("bc_svc_process() returned w/ error code= %d\n",
	169	error);
	170	} else {
	171	spin_unlock_bh(&serv->sv_cb_lock);
	172	schedule();
	173	}
	174	finish_wait(&serv->sv_cb_waitq, &wq);
	175	}
	176	unlock_kernel();
	177	nfs_callback_info.task = NULL;
	178	svc_exit_thread(rqstp);
	179	return 0;
	180	}
	181
	182	/*
	183	* Bring up the NFSv4.1 callback service
	184	*/
	185	struct svc_rqst *
	186	nfs41_callback_up(struct svc_serv serv, struct rpc_xprt xprt)
	187	{
8f975242 BH	188	struct svc_xprt *bc_xprt;
	189	struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
	190
	191	dprintk("--> %s\n", __func__);
	192	/* Create a svc_sock for the service */
	193	bc_xprt = svc_sock_create(serv, xprt->prot);
	194	if (!bc_xprt)
	195	goto out;
	196
a43cde94 RL	197	/*
	198	* Save the svc_serv in the transport so that it can
	199	* be referenced when the session backchannel is initialized
	200	*/
8f975242	201	serv->bc_xprt = bc_xprt;
a43cde94 RL	202	xprt->bc_serv = serv;
	203
	204	INIT_LIST_HEAD(&serv->sv_cb_list);
	205	spin_lock_init(&serv->sv_cb_lock);
	206	init_waitqueue_head(&serv->sv_cb_waitq);
8f975242 BH	207	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
	208	if (IS_ERR(rqstp))
	209	svc_sock_destroy(bc_xprt);
	210	out:
	211	dprintk("--> %s return %p\n", __func__, rqstp);
	212	return rqstp;
a43cde94 RL	213	}
	214
	215	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	216	struct svc_serv serv, struct rpc_xprt xprt,
	217	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	218	{
	219	if (minorversion) {
	220	*rqstpp = nfs41_callback_up(serv, xprt);
	221	*callback_svc = nfs41_callback_svc;
	222	}
	223	return minorversion;
	224	}
	225
	226	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	227	struct nfs_callback_data *cb_info)
	228	{
	229	if (minorversion)
	230	xprt->bc_serv = cb_info->serv;
	231	}
	232	#else
	233	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	234	struct svc_serv serv, struct rpc_xprt xprt,
	235	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	236	{
	237	return 0;
	238	}
	239
	240	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	241	struct nfs_callback_data *cb_info)
	242	{
	243	}
	244	#endif /* CONFIG_NFS_V4_1 */
	245
71468513 BH	246	/*
	247	* Bring up the callback thread if it is not already up.
	248	*/
	249	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	250	{
	251	struct svc_serv *serv = NULL;
	252	struct svc_rqst *rqstp;
	253	int (callback_svc)(void vrqstp);
	254	char svc_name[12];
	255	int ret = 0;
a43cde94	256	int minorversion_setup;
71468513 BH	257
71468513 BH	258	mutex_lock(&nfs_callback_mutex);
a43cde94 RL	259	if (nfs_callback_info.users++ \|\| nfs_callback_info.task != NULL) {
a43cde94 RL	260	nfs_callback_bc_serv(minorversion, xprt, &nfs_callback_info);
71468513	261	goto out;
a43cde94	262	}
71468513 BH	263	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	264	if (!serv) {
	265	ret = -ENOMEM;
	266	goto out_err;
	267	}
	268
a43cde94 RL	269	minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
	270	serv, xprt, &rqstp, &callback_svc);
	271	if (!minorversion_setup) {
	272	/* v4.0 callback setup */
71468513 BH	273	rqstp = nfs4_callback_up(serv);
71468513 BH	274	callback_svc = nfs4_callback_svc;
71468513 BH	275	}
	276
	277	if (IS_ERR(rqstp)) {
	278	ret = PTR_ERR(rqstp);
8e60029f	279	goto out_err;
a277e33c JL	280	}
	281
	282	svc_sock_update_bufs(serv);
a277e33c	283
71468513	284	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
a43cde94	285	nfs_callback_info.serv = serv;
71468513 BH	286	nfs_callback_info.rqst = rqstp;
71468513 BH	287	nfs_callback_info.task = kthread_run(callback_svc,
5afc597c	288	nfs_callback_info.rqst,
71468513	289	svc_name);
a277e33c JL	290	if (IS_ERR(nfs_callback_info.task)) {
a277e33c JL	291	ret = PTR_ERR(nfs_callback_info.task);
5afc597c	292	svc_exit_thread(nfs_callback_info.rqst);
a43cde94	293	nfs_callback_info.serv = NULL;
5afc597c	294	nfs_callback_info.rqst = NULL;
a277e33c	295	nfs_callback_info.task = NULL;
a277e33c JL	296	goto out_err;
a277e33c JL	297	}
1da177e4	298	out:
8e60029f JL	299	/*
8e60029f JL	300	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	301	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	302	* on both success and failure so that the refcount is 1 when the
	303	* thread exits.
	304	*/
	305	if (serv)
	306	svc_destroy(serv);
353ab6e9	307	mutex_unlock(&nfs_callback_mutex);
1da177e4	308	return ret;
8e60029f	309	out_err:
18de9735 CL	310	dprintk("NFS: Couldn't create callback socket or server thread; "
18de9735 CL	311	"err = %d\n", ret);
1da177e4 LT	312	nfs_callback_info.users--;
	313	goto out;
	314	}
	315
	316	/*
5afc597c	317	* Kill the callback thread if it's no longer being used.
1da177e4	318	*/
5ae1fbce	319	void nfs_callback_down(void)
1da177e4	320	{
353ab6e9	321	mutex_lock(&nfs_callback_mutex);
1dd761e9	322	nfs_callback_info.users--;
5afc597c	323	if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) {
a277e33c	324	kthread_stop(nfs_callback_info.task);
5afc597c	325	svc_exit_thread(nfs_callback_info.rqst);
a43cde94	326	nfs_callback_info.serv = NULL;
5afc597c JL	327	nfs_callback_info.rqst = NULL;
	328	nfs_callback_info.task = NULL;
	329	}
353ab6e9	330	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	331	}
1da177e4 LT	332
945b34a7 OK	333	static int check_gss_callback_principal(struct nfs_client *clp,
	334	struct svc_rqst *rqstp)
	335	{
	336	struct rpc_clnt *r = clp->cl_rpcclient;
	337	char *p = svc_gss_principal(rqstp);
	338
	339	/*
	340	* It might just be a normal user principal, in which case
	341	* userspace won't bother to tell us the name at all.
	342	*/
	343	if (p == NULL)
	344	return SVC_DENIED;
	345
	346	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	347
	348	if (memcmp(p, "nfs@", 4) != 0)
	349	return SVC_DENIED;
	350	p += 4;
	351	if (strcmp(p, r->cl_server) != 0)
	352	return SVC_DENIED;
	353	return SVC_OK;
	354	}
	355
1da177e4 LT	356	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	357	{
adfa6f98	358	struct nfs_client *clp;
5216a8e7	359	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
945b34a7	360	int ret = SVC_OK;
1da177e4 LT	361
1da177e4 LT	362	/* Don't talk to strangers */
ff052645	363	clp = nfs_find_client(svc_addr(rqstp), 4);
1da177e4 LT	364	if (clp == NULL)
1da177e4 LT	365	return SVC_DROP;
ad06e4bd	366
3110ff80	367	dprintk("%s: %s NFSv4 callback!\n", __func__,
ad06e4bd	368	svc_print_addr(rqstp, buf, sizeof(buf)));
ad06e4bd	369
1da177e4 LT	370	switch (rqstp->rq_authop->flavour) {
	371	case RPC_AUTH_NULL:
	372	if (rqstp->rq_proc != CB_NULL)
945b34a7	373	ret = SVC_DENIED;
1da177e4 LT	374	break;
	375	case RPC_AUTH_UNIX:
	376	break;
	377	case RPC_AUTH_GSS:
945b34a7 OK	378	ret = check_gss_callback_principal(clp, rqstp);
945b34a7 OK	379	break;
1da177e4	380	default:
945b34a7	381	ret = SVC_DENIED;
1da177e4	382	}
945b34a7 OK	383	nfs_put_client(clp);
945b34a7 OK	384	return ret;
1da177e4 LT	385	}
	386
	387	/*
	388	* Define NFS4 callback program
	389	*/
1da177e4 LT	390	static struct svc_version *nfs4_callback_version[] = {
	391	[1] = &nfs4_callback_version1,
	392	};
	393
	394	static struct svc_stat nfs4_callback_stats;
	395
	396	static struct svc_program nfs4_callback_program = {
	397	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	398	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	399	.pg_vers = nfs4_callback_version, /* version table */
	400	.pg_name = "NFSv4 callback", /* service name */
	401	.pg_class = "nfs", /* authentication class */
	402	.pg_stats = &nfs4_callback_stats,
	403	.pg_authenticate = nfs_callback_authenticate,
	404	};