[net-next-2.6.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, const 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 struct kernel_param_ops param_ops_portnr = {
	.set = param_set_portnr,
	.get = param_get_uint,
};
#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", &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]);

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
9bbb9e5a	48	static int param_set_portnr(const char val, const 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;
7d4e2747 DH	60	}
9bbb9e5a RR	61	static struct kernel_param_ops param_ops_portnr = {
	62	.set = param_set_portnr,
	63	.get = param_get_uint,
	64	};
c140aa91 TM	65	#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
	66
	67	module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1da177e4 LT	68
1da177e4 LT	69	/*
e82dc22d	70	* This is the NFSv4 callback kernel thread.
1da177e4	71	*/
a277e33c	72	static int
71468513	73	nfs4_callback_svc(void *vrqstp)
1da177e4	74	{
06e02d66	75	int err, preverr = 0;
a277e33c	76	struct svc_rqst *rqstp = vrqstp;
1da177e4	77
83144186	78	set_freezable();
1da177e4	79
a277e33c	80	while (!kthread_should_stop()) {
1da177e4 LT	81	/*
	82	* Listen for a request on the socket
	83	*/
6fb2b47f	84	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
06e02d66 JL	85	if (err == -EAGAIN \|\| err == -EINTR) {
06e02d66 JL	86	preverr = err;
1da177e4	87	continue;
06e02d66	88	}
1da177e4	89	if (err < 0) {
06e02d66 JL	90	if (err != preverr) {
	91	printk(KERN_WARNING "%s: unexpected error "
	92	"from svc_recv (%d)\n", __func__, err);
	93	preverr = err;
	94	}
	95	schedule_timeout_uninterruptible(HZ);
	96	continue;
1da177e4	97	}
06e02d66	98	preverr = err;
6fb2b47f	99	svc_process(rqstp);
1da177e4	100	}
a277e33c	101	return 0;
1da177e4 LT	102	}
	103
	104	/*
71468513	105	* Prepare to bring up the NFSv4 callback service
1da177e4	106	*/
71468513 BH	107	struct svc_rqst *
71468513 BH	108	nfs4_callback_up(struct svc_serv *serv)
1da177e4	109	{
71468513	110	int ret;
482fb94e	111
fc5d00b0	112	ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET,
9652ada3	113	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
482fb94e	114	if (ret <= 0)
8e60029f	115	goto out_err;
482fb94e	116	nfs_callback_tcpport = ret;
18de9735	117	dprintk("NFS: Callback listener port = %u (af %u)\n",
26298caa	118	nfs_callback_tcpport, PF_INET);
482fb94e	119
fc5d00b0	120	ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET6,
f738f517 CL	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);
18fc3164 CL	126	} else if (ret == -EAFNOSUPPORT)
	127	ret = 0;
	128	else
f738f517	129	goto out_err;
f738f517	130
71468513 BH	131	return svc_prepare_thread(serv, &serv->sv_pools[0]);
	132
	133	out_err:
	134	if (ret == 0)
	135	ret = -ENOMEM;
	136	return ERR_PTR(ret);
	137	}
	138
a43cde94 RL	139	#if defined(CONFIG_NFS_V4_1)
	140	/*
	141	* The callback service for NFSv4.1 callbacks
	142	*/
	143	static int
	144	nfs41_callback_svc(void *vrqstp)
	145	{
	146	struct svc_rqst *rqstp = vrqstp;
	147	struct svc_serv *serv = rqstp->rq_server;
	148	struct rpc_rqst *req;
	149	int error;
	150	DEFINE_WAIT(wq);
	151
	152	set_freezable();
	153
a43cde94 RL	154	while (!kthread_should_stop()) {
	155	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	156	spin_lock_bh(&serv->sv_cb_lock);
	157	if (!list_empty(&serv->sv_cb_list)) {
	158	req = list_first_entry(&serv->sv_cb_list,
	159	struct rpc_rqst, rq_bc_list);
	160	list_del(&req->rq_bc_list);
	161	spin_unlock_bh(&serv->sv_cb_lock);
	162	dprintk("Invoking bc_svc_process()\n");
	163	error = bc_svc_process(serv, req, rqstp);
	164	dprintk("bc_svc_process() returned w/ error code= %d\n",
	165	error);
	166	} else {
	167	spin_unlock_bh(&serv->sv_cb_lock);
	168	schedule();
	169	}
	170	finish_wait(&serv->sv_cb_waitq, &wq);
	171	}
a43cde94 RL	172	return 0;
	173	}
	174
	175	/*
	176	* Bring up the NFSv4.1 callback service
	177	*/
	178	struct svc_rqst *
	179	nfs41_callback_up(struct svc_serv serv, struct rpc_xprt xprt)
	180	{
8f975242 BH	181	struct svc_xprt *bc_xprt;
	182	struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
	183
	184	dprintk("--> %s\n", __func__);
	185	/* Create a svc_sock for the service */
	186	bc_xprt = svc_sock_create(serv, xprt->prot);
	187	if (!bc_xprt)
	188	goto out;
	189
a43cde94 RL	190	/*
	191	* Save the svc_serv in the transport so that it can
	192	* be referenced when the session backchannel is initialized
	193	*/
8f975242	194	serv->bc_xprt = bc_xprt;
a43cde94 RL	195	xprt->bc_serv = serv;
	196
	197	INIT_LIST_HEAD(&serv->sv_cb_list);
	198	spin_lock_init(&serv->sv_cb_lock);
	199	init_waitqueue_head(&serv->sv_cb_waitq);
8f975242 BH	200	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
	201	if (IS_ERR(rqstp))
	202	svc_sock_destroy(bc_xprt);
	203	out:
	204	dprintk("--> %s return %p\n", __func__, rqstp);
	205	return rqstp;
a43cde94 RL	206	}
	207
	208	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	209	struct svc_serv serv, struct rpc_xprt xprt,
	210	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	211	{
	212	if (minorversion) {
	213	*rqstpp = nfs41_callback_up(serv, xprt);
	214	*callback_svc = nfs41_callback_svc;
	215	}
	216	return minorversion;
	217	}
	218
	219	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	220	struct nfs_callback_data *cb_info)
	221	{
	222	if (minorversion)
	223	xprt->bc_serv = cb_info->serv;
	224	}
	225	#else
	226	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	227	struct svc_serv serv, struct rpc_xprt xprt,
	228	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	229	{
	230	return 0;
	231	}
	232
	233	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	234	struct nfs_callback_data *cb_info)
	235	{
	236	}
	237	#endif /* CONFIG_NFS_V4_1 */
	238
71468513 BH	239	/*
	240	* Bring up the callback thread if it is not already up.
	241	*/
	242	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	243	{
	244	struct svc_serv *serv = NULL;
	245	struct svc_rqst *rqstp;
	246	int (callback_svc)(void vrqstp);
e82dc22d	247	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
71468513 BH	248	char svc_name[12];
71468513 BH	249	int ret = 0;
a43cde94	250	int minorversion_setup;
71468513 BH	251
71468513 BH	252	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	253	if (cb_info->users++ \|\| cb_info->task != NULL) {
e82dc22d AA	254	nfs_callback_bc_serv(minorversion, xprt, cb_info);
71468513	255	goto out;
a43cde94	256	}
71468513 BH	257	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	258	if (!serv) {
	259	ret = -ENOMEM;
	260	goto out_err;
	261	}
	262
a43cde94 RL	263	minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
	264	serv, xprt, &rqstp, &callback_svc);
	265	if (!minorversion_setup) {
	266	/* v4.0 callback setup */
71468513 BH	267	rqstp = nfs4_callback_up(serv);
71468513 BH	268	callback_svc = nfs4_callback_svc;
71468513 BH	269	}
	270
	271	if (IS_ERR(rqstp)) {
	272	ret = PTR_ERR(rqstp);
8e60029f	273	goto out_err;
a277e33c JL	274	}
	275
	276	svc_sock_update_bufs(serv);
a277e33c	277
71468513	278	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
e82dc22d AA	279	cb_info->serv = serv;
	280	cb_info->rqst = rqstp;
	281	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
	282	if (IS_ERR(cb_info->task)) {
	283	ret = PTR_ERR(cb_info->task);
	284	svc_exit_thread(cb_info->rqst);
	285	cb_info->rqst = NULL;
	286	cb_info->task = NULL;
a277e33c JL	287	goto out_err;
a277e33c JL	288	}
1da177e4	289	out:
8e60029f JL	290	/*
8e60029f JL	291	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	292	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	293	* on both success and failure so that the refcount is 1 when the
	294	* thread exits.
	295	*/
	296	if (serv)
	297	svc_destroy(serv);
353ab6e9	298	mutex_unlock(&nfs_callback_mutex);
1da177e4	299	return ret;
8e60029f	300	out_err:
18de9735 CL	301	dprintk("NFS: Couldn't create callback socket or server thread; "
18de9735 CL	302	"err = %d\n", ret);
e82dc22d	303	cb_info->users--;
1da177e4 LT	304	goto out;
	305	}
	306
	307	/*
5afc597c	308	* Kill the callback thread if it's no longer being used.
1da177e4	309	*/
e82dc22d	310	void nfs_callback_down(int minorversion)
1da177e4	311	{
e82dc22d AA	312	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	313
353ab6e9	314	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	315	cb_info->users--;
	316	if (cb_info->users == 0 && cb_info->task != NULL) {
	317	kthread_stop(cb_info->task);
	318	svc_exit_thread(cb_info->rqst);
	319	cb_info->serv = NULL;
	320	cb_info->rqst = NULL;
	321	cb_info->task = NULL;
5afc597c	322	}
353ab6e9	323	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	324	}
1da177e4 LT	325
945b34a7 OK	326	static int check_gss_callback_principal(struct nfs_client *clp,
	327	struct svc_rqst *rqstp)
	328	{
	329	struct rpc_clnt *r = clp->cl_rpcclient;
	330	char *p = svc_gss_principal(rqstp);
	331
	332	/*
	333	* It might just be a normal user principal, in which case
	334	* userspace won't bother to tell us the name at all.
	335	*/
	336	if (p == NULL)
	337	return SVC_DENIED;
	338
	339	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	340
	341	if (memcmp(p, "nfs@", 4) != 0)
	342	return SVC_DENIED;
	343	p += 4;
	344	if (strcmp(p, r->cl_server) != 0)
	345	return SVC_DENIED;
	346	return SVC_OK;
	347	}
	348
1da177e4 LT	349	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	350	{
adfa6f98	351	struct nfs_client *clp;
5216a8e7	352	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
945b34a7	353	int ret = SVC_OK;
1da177e4 LT	354
1da177e4 LT	355	/* Don't talk to strangers */
ff052645	356	clp = nfs_find_client(svc_addr(rqstp), 4);
1da177e4 LT	357	if (clp == NULL)
1da177e4 LT	358	return SVC_DROP;
ad06e4bd	359
3110ff80	360	dprintk("%s: %s NFSv4 callback!\n", __func__,
ad06e4bd	361	svc_print_addr(rqstp, buf, sizeof(buf)));
ad06e4bd	362
1da177e4 LT	363	switch (rqstp->rq_authop->flavour) {
	364	case RPC_AUTH_NULL:
	365	if (rqstp->rq_proc != CB_NULL)
945b34a7	366	ret = SVC_DENIED;
1da177e4 LT	367	break;
	368	case RPC_AUTH_UNIX:
	369	break;
	370	case RPC_AUTH_GSS:
945b34a7 OK	371	ret = check_gss_callback_principal(clp, rqstp);
945b34a7 OK	372	break;
1da177e4	373	default:
945b34a7	374	ret = SVC_DENIED;
1da177e4	375	}
945b34a7 OK	376	nfs_put_client(clp);
945b34a7 OK	377	return ret;
1da177e4 LT	378	}
	379
	380	/*
	381	* Define NFS4 callback program
	382	*/
1da177e4 LT	383	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	384	[1] = &nfs4_callback_version1,
07bccc2d	385	[4] = &nfs4_callback_version4,
1da177e4 LT	386	};
	387
	388	static struct svc_stat nfs4_callback_stats;
	389
	390	static struct svc_program nfs4_callback_program = {
	391	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	392	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	393	.pg_vers = nfs4_callback_version, /* version table */
	394	.pg_name = "NFSv4 callback", /* service name */
	395	.pg_class = "nfs", /* authentication class */
	396	.pg_stats = &nfs4_callback_stats,
	397	.pg_authenticate = nfs_callback_authenticate,
	398	};