[deliverable/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 <linux/nsproxy.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 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 "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", xprt->xprt_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", xprt->xprt_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", xprt->xprt_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 = current->nsproxy->net_ns;

	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;
	}

	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, current->nsproxy->net_ns);
		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 = svc_gss_principal(rqstp);

	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>
9793f7c8	20	#include <linux/nsproxy.h>
14c85021 ACM	21
	22	#include <net/inet_sock.h>
	23
4ce79717	24	#include "nfs4_fs.h"
1da177e4	25	#include "callback.h"
24c8dbbb	26	#include "internal.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
a72b4422	41	unsigned int nfs_callback_set_tcpport;
1da177e4	42	unsigned short nfs_callback_tcpport;
f738f517	43	unsigned short nfs_callback_tcpport6;
c140aa91	44	#define NFS_CALLBACK_MAXPORTNR (65535U)
7d4e2747	45
9bbb9e5a	46	static int param_set_portnr(const char val, const struct kernel_param kp)
7d4e2747	47	{
c140aa91 TM	48	unsigned long num;
	49	int ret;
	50
	51	if (!val)
	52	return -EINVAL;
	53	ret = strict_strtoul(val, 0, &num);
	54	if (ret == -EINVAL \|\| num > NFS_CALLBACK_MAXPORTNR)
7d4e2747	55	return -EINVAL;
c140aa91	56	((unsigned int )kp->arg) = num;
7d4e2747 DH	57	return 0;
7d4e2747 DH	58	}
9bbb9e5a RR	59	static struct kernel_param_ops param_ops_portnr = {
	60	.set = param_set_portnr,
	61	.get = param_get_uint,
	62	};
c140aa91 TM	63	#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
	64
	65	module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1da177e4 LT	66
1da177e4 LT	67	/*
e82dc22d	68	* This is the NFSv4 callback kernel thread.
1da177e4	69	*/
a277e33c	70	static int
71468513	71	nfs4_callback_svc(void *vrqstp)
1da177e4	72	{
06e02d66	73	int err, preverr = 0;
a277e33c	74	struct svc_rqst *rqstp = vrqstp;
1da177e4	75
83144186	76	set_freezable();
1da177e4	77
a277e33c	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	88	if (err != preverr) {
a030889a	89	printk(KERN_WARNING "NFS: %s: unexpected error "
06e02d66 JL	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	}
a277e33c	99	return 0;
1da177e4 LT	100	}
	101
	102	/*
71468513	103	* Prepare to bring up the NFSv4 callback service
1da177e4	104	*/
17280175	105	static struct svc_rqst *
7bb782c6	106	nfs4_callback_up(struct svc_serv serv, struct rpc_xprt xprt)
1da177e4	107	{
71468513	108	int ret;
482fb94e	109
7bb782c6	110	ret = svc_create_xprt(serv, "tcp", xprt->xprt_net, PF_INET,
9652ada3	111	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
482fb94e	112	if (ret <= 0)
8e60029f	113	goto out_err;
482fb94e	114	nfs_callback_tcpport = ret;
18de9735	115	dprintk("NFS: Callback listener port = %u (af %u)\n",
26298caa	116	nfs_callback_tcpport, PF_INET);
482fb94e	117
7bb782c6	118	ret = svc_create_xprt(serv, "tcp", xprt->xprt_net, PF_INET6,
f738f517 CL	119	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	120	if (ret > 0) {
	121	nfs_callback_tcpport6 = ret;
	122	dprintk("NFS: Callback listener port = %u (af %u)\n",
	123	nfs_callback_tcpport6, PF_INET6);
18fc3164 CL	124	} else if (ret == -EAFNOSUPPORT)
	125	ret = 0;
	126	else
f738f517	127	goto out_err;
f738f517	128
11fd165c	129	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
71468513 BH	130
	131	out_err:
	132	if (ret == 0)
	133	ret = -ENOMEM;
	134	return ERR_PTR(ret);
	135	}
	136
a43cde94 RL	137	#if defined(CONFIG_NFS_V4_1)
	138	/*
	139	* The callback service for NFSv4.1 callbacks
	140	*/
	141	static int
	142	nfs41_callback_svc(void *vrqstp)
	143	{
	144	struct svc_rqst *rqstp = vrqstp;
	145	struct svc_serv *serv = rqstp->rq_server;
	146	struct rpc_rqst *req;
	147	int error;
	148	DEFINE_WAIT(wq);
	149
	150	set_freezable();
	151
a43cde94 RL	152	while (!kthread_should_stop()) {
	153	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	154	spin_lock_bh(&serv->sv_cb_lock);
	155	if (!list_empty(&serv->sv_cb_list)) {
	156	req = list_first_entry(&serv->sv_cb_list,
	157	struct rpc_rqst, rq_bc_list);
	158	list_del(&req->rq_bc_list);
	159	spin_unlock_bh(&serv->sv_cb_lock);
	160	dprintk("Invoking bc_svc_process()\n");
	161	error = bc_svc_process(serv, req, rqstp);
	162	dprintk("bc_svc_process() returned w/ error code= %d\n",
	163	error);
	164	} else {
	165	spin_unlock_bh(&serv->sv_cb_lock);
	166	schedule();
	167	}
	168	finish_wait(&serv->sv_cb_waitq, &wq);
	169	}
a43cde94 RL	170	return 0;
	171	}
	172
	173	/*
	174	* Bring up the NFSv4.1 callback service
	175	*/
17280175	176	static struct svc_rqst *
a43cde94 RL	177	nfs41_callback_up(struct svc_serv serv, struct rpc_xprt xprt)
a43cde94 RL	178	{
01c9a0bc AA	179	struct svc_rqst *rqstp;
01c9a0bc AA	180	int ret;
8f975242	181
01c9a0bc AA	182	/*
	183	* Create an svc_sock for the back channel service that shares the
	184	* fore channel connection.
	185	* Returns the input port (0) and sets the svc_serv bc_xprt on success
	186	*/
7bb782c6	187	ret = svc_create_xprt(serv, "tcp-bc", xprt->xprt_net, PF_INET, 0,
01c9a0bc AA	188	SVC_SOCK_ANONYMOUS);
	189	if (ret < 0) {
	190	rqstp = ERR_PTR(ret);
8f975242	191	goto out;
01c9a0bc	192	}
8f975242	193
a43cde94 RL	194	/*
	195	* Save the svc_serv in the transport so that it can
	196	* be referenced when the session backchannel is initialized
	197	*/
	198	xprt->bc_serv = serv;
	199
	200	INIT_LIST_HEAD(&serv->sv_cb_list);
	201	spin_lock_init(&serv->sv_cb_lock);
	202	init_waitqueue_head(&serv->sv_cb_waitq);
11fd165c	203	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
01c9a0bc	204	if (IS_ERR(rqstp)) {
4a19de0f AA	205	svc_xprt_put(serv->sv_bc_xprt);
4a19de0f AA	206	serv->sv_bc_xprt = NULL;
01c9a0bc	207	}
8f975242	208	out:
01c9a0bc AA	209	dprintk("--> %s return %ld\n", __func__,
01c9a0bc AA	210	IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
8f975242	211	return rqstp;
a43cde94 RL	212	}
	213
	214	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	215	struct svc_serv serv, struct rpc_xprt xprt,
	216	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	217	{
	218	if (minorversion) {
	219	*rqstpp = nfs41_callback_up(serv, xprt);
	220	*callback_svc = nfs41_callback_svc;
	221	}
	222	return minorversion;
	223	}
	224
	225	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	226	struct nfs_callback_data *cb_info)
	227	{
	228	if (minorversion)
	229	xprt->bc_serv = cb_info->serv;
	230	}
	231	#else
	232	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	233	struct svc_serv serv, struct rpc_xprt xprt,
	234	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	235	{
	236	return 0;
	237	}
	238
	239	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	240	struct nfs_callback_data *cb_info)
	241	{
	242	}
	243	#endif /* CONFIG_NFS_V4_1 */
	244
71468513 BH	245	/*
	246	* Bring up the callback thread if it is not already up.
	247	*/
	248	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	249	{
	250	struct svc_serv *serv = NULL;
	251	struct svc_rqst *rqstp;
	252	int (callback_svc)(void vrqstp);
e82dc22d	253	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
71468513 BH	254	char svc_name[12];
71468513 BH	255	int ret = 0;
a43cde94	256	int minorversion_setup;
9793f7c8	257	struct net *net = current->nsproxy->net_ns;
71468513 BH	258
71468513 BH	259	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	260	if (cb_info->users++ \|\| cb_info->task != NULL) {
e82dc22d AA	261	nfs_callback_bc_serv(minorversion, xprt, cb_info);
71468513	262	goto out;
a43cde94	263	}
71468513 BH	264	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	265	if (!serv) {
	266	ret = -ENOMEM;
	267	goto out_err;
	268	}
	269
9793f7c8 SK	270	ret = svc_bind(serv, net);
	271	if (ret < 0) {
	272	printk(KERN_WARNING "NFS: bind callback service failed\n");
	273	goto out_err;
	274	}
	275
a43cde94 RL	276	minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
	277	serv, xprt, &rqstp, &callback_svc);
	278	if (!minorversion_setup) {
	279	/* v4.0 callback setup */
7bb782c6	280	rqstp = nfs4_callback_up(serv, xprt);
71468513	281	callback_svc = nfs4_callback_svc;
71468513 BH	282	}
	283
	284	if (IS_ERR(rqstp)) {
	285	ret = PTR_ERR(rqstp);
8e60029f	286	goto out_err;
a277e33c JL	287	}
	288
	289	svc_sock_update_bufs(serv);
a277e33c	290
71468513	291	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
e82dc22d AA	292	cb_info->serv = serv;
	293	cb_info->rqst = rqstp;
	294	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
	295	if (IS_ERR(cb_info->task)) {
	296	ret = PTR_ERR(cb_info->task);
	297	svc_exit_thread(cb_info->rqst);
	298	cb_info->rqst = NULL;
	299	cb_info->task = NULL;
a277e33c JL	300	goto out_err;
a277e33c JL	301	}
1da177e4	302	out:
8e60029f JL	303	/*
8e60029f JL	304	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	305	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	306	* on both success and failure so that the refcount is 1 when the
	307	* thread exits.
	308	*/
	309	if (serv)
	310	svc_destroy(serv);
353ab6e9	311	mutex_unlock(&nfs_callback_mutex);
1da177e4	312	return ret;
8e60029f	313	out_err:
18de9735 CL	314	dprintk("NFS: Couldn't create callback socket or server thread; "
18de9735 CL	315	"err = %d\n", ret);
e82dc22d	316	cb_info->users--;
786185b5 SK	317	if (serv)
786185b5 SK	318	svc_shutdown_net(serv, net);
1da177e4 LT	319	goto out;
	320	}
	321
	322	/*
5afc597c	323	* Kill the callback thread if it's no longer being used.
1da177e4	324	*/
e82dc22d	325	void nfs_callback_down(int minorversion)
1da177e4	326	{
e82dc22d AA	327	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	328
353ab6e9	329	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	330	cb_info->users--;
	331	if (cb_info->users == 0 && cb_info->task != NULL) {
	332	kthread_stop(cb_info->task);
786185b5	333	svc_shutdown_net(cb_info->serv, current->nsproxy->net_ns);
e82dc22d AA	334	svc_exit_thread(cb_info->rqst);
	335	cb_info->serv = NULL;
	336	cb_info->rqst = NULL;
	337	cb_info->task = NULL;
5afc597c	338	}
353ab6e9	339	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	340	}
1da177e4 LT	341
778be232 AA	342	/* Boolean check of RPC_AUTH_GSS principal */
	343	int
	344	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	345	{
945b34a7 OK	346	char *p = svc_gss_principal(rqstp);
945b34a7 OK	347
778be232 AA	348	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	349	return 1;
	350
ece0de63 AA	351	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	352	if (clp->cl_minorversion != 0)
778be232	353	return 0;
945b34a7 OK	354	/*
	355	* It might just be a normal user principal, in which case
	356	* userspace won't bother to tell us the name at all.
	357	*/
	358	if (p == NULL)
778be232	359	return 0;
945b34a7 OK	360
	361	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	362
	363	if (memcmp(p, "nfs@", 4) != 0)
778be232	364	return 0;
945b34a7	365	p += 4;
4e0038b6	366	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	367	return 0;
778be232 AA	368	return 1;
945b34a7 OK	369	}
945b34a7 OK	370
778be232 AA	371	/*
	372	* pg_authenticate method for nfsv4 callback threads.
	373	*
	374	* The authflavor has been negotiated, so an incorrect flavor is a server
	375	* bug. Drop packets with incorrect authflavor.
	376	*
	377	* All other checking done after NFS decoding where the nfs_client can be
	378	* found in nfs4_callback_compound
	379	*/
1da177e4 LT	380	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	381	{
1da177e4	382	switch (rqstp->rq_authop->flavour) {
778be232 AA	383	case RPC_AUTH_NULL:
	384	if (rqstp->rq_proc != CB_NULL)
	385	return SVC_DROP;
	386	break;
	387	case RPC_AUTH_GSS:
	388	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	389	if (svc_is_backchannel(rqstp))
	390	return SVC_DROP;
1da177e4	391	}
778be232	392	return SVC_OK;
1da177e4 LT	393	}
	394
	395	/*
	396	* Define NFS4 callback program
	397	*/
1da177e4 LT	398	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	399	[1] = &nfs4_callback_version1,
07bccc2d	400	[4] = &nfs4_callback_version4,
1da177e4 LT	401	};
	402
	403	static struct svc_stat nfs4_callback_stats;
	404
	405	static struct svc_program nfs4_callback_program = {
	406	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	407	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	408	.pg_vers = nfs4_callback_version, /* version table */
	409	.pg_name = "NFSv4 callback", /* service name */
	410	.pg_class = "nfs", /* authentication class */
	411	.pg_stats = &nfs4_callback_stats,
	412	.pg_authenticate = nfs_callback_authenticate,
	413	};