[mirror_ubuntu-zesty-kernel.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/errno.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"
#include "netns.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;

static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
{
	int ret;
	struct nfs_net *nn = net_generic(net, nfs_net_id);

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

	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	if (ret > 0) {
		nn->nfs_callback_tcpport6 = ret;
		dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
				nn->nfs_callback_tcpport6, PF_INET6, net);
	} else if (ret != -EAFNOSUPPORT)
		goto out_err;
	return 0;

out_err:
	return (ret) ? ret : -ENOMEM;
}

/*
 * This is the NFSv4 callback kernel thread.
 */
static int
nfs4_callback_svc(void *vrqstp)
{
	int err;
	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)
			continue;
		svc_process(rqstp);
	}
	return 0;
}

/*
 * Prepare to bring up the NFSv4 callback service
 */
static struct svc_rqst *
nfs4_callback_up(struct svc_serv *serv)
{
	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
}

#if defined(CONFIG_NFS_V4_1)
static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
{
	/*
	 * 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
	 */
	return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
			      SVC_SOCK_ANONYMOUS);
}

/*
 * 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()) {
		if (try_to_freeze())
			continue;

		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 svc_rqst *rqstp;

	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;
	}
	dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
	return rqstp;
}

static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
	*rqstpp = nfs41_callback_up(serv);
	*callback_svc = nfs41_callback_svc;
}

static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
		struct svc_serv *serv)
{
	if (minorversion)
		/*
		 * Save the svc_serv in the transport so that it can
		 * be referenced when the session backchannel is initialized
		 */
		xprt->bc_serv = serv;
}
#else
static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
{
	return 0;
}

static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
		struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
	*rqstpp = ERR_PTR(-ENOTSUPP);
	*callback_svc = ERR_PTR(-ENOTSUPP);
}

static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
		struct svc_serv *serv)
{
}
#endif /* CONFIG_NFS_V4_1 */

static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
				  struct svc_serv *serv)
{
	struct svc_rqst *rqstp;
	int (*callback_svc)(void *vrqstp);
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	int ret;

	nfs_callback_bc_serv(minorversion, xprt, serv);

	if (cb_info->task)
		return 0;

	switch (minorversion) {
	case 0:
		/* v4.0 callback setup */
		rqstp = nfs4_callback_up(serv);
		callback_svc = nfs4_callback_svc;
		break;
	default:
		nfs_minorversion_callback_svc_setup(serv,
				&rqstp, &callback_svc);
	}

	if (IS_ERR(rqstp))
		return PTR_ERR(rqstp);

	svc_sock_update_bufs(serv);

	cb_info->serv = serv;
	cb_info->rqst = rqstp;
	cb_info->task = kthread_run(callback_svc, cb_info->rqst,
				    "nfsv4.%u-svc", minorversion);
	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;
		return ret;
	}
	dprintk("nfs_callback_up: service started\n");
	return 0;
}

static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
{
	struct nfs_net *nn = net_generic(net, nfs_net_id);

	if (--nn->cb_users[minorversion])
		return;

	dprintk("NFS: destroy per-net callback data; net=%p\n", net);
	svc_shutdown_net(serv, net);
}

static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
{
	struct nfs_net *nn = net_generic(net, nfs_net_id);
	int ret;

	if (nn->cb_users[minorversion]++)
		return 0;

	dprintk("NFS: create per-net callback data; net=%p\n", net);

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

	switch (minorversion) {
		case 0:
			ret = nfs4_callback_up_net(serv, net);
			break;
		case 1:
		case 2:
			ret = nfs41_callback_up_net(serv, net);
			break;
		default:
			printk(KERN_ERR "NFS: unknown callback version: %d\n",
					minorversion);
			ret = -EINVAL;
			break;
	}

	if (ret < 0) {
		printk(KERN_ERR "NFS: callback service start failed\n");
		goto err_socks;
	}
	return 0;

err_socks:
	svc_rpcb_cleanup(serv, net);
err_bind:
	dprintk("NFS: Couldn't create callback socket: err = %d; "
			"net = %p\n", ret, net);
	return ret;
}

static struct svc_serv *nfs_callback_create_svc(int minorversion)
{
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	struct svc_serv *serv;

	/*
	 * Check whether we're already up and running.
	 */
	if (cb_info->task) {
		/*
		 * Note: increase service usage, because later in case of error
		 * svc_destroy() will be called.
		 */
		svc_get(cb_info->serv);
		return cb_info->serv;
	}

	/*
	 * Sanity check: if there's no task,
	 * we should be the first user ...
	 */
	if (cb_info->users)
		printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
			cb_info->users);

	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	if (!serv) {
		printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
		return ERR_PTR(-ENOMEM);
	}
	/* As there is only one thread we need to over-ride the
	 * default maximum of 80 connections
	 */
	serv->sv_maxconn = 1024;
	dprintk("nfs_callback_create_svc: service created\n");
	return serv;
}

/*
 * 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;
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	int ret;
	struct net *net = xprt->xprt_net;

	mutex_lock(&nfs_callback_mutex);

	serv = nfs_callback_create_svc(minorversion);
	if (IS_ERR(serv)) {
		ret = PTR_ERR(serv);
		goto err_create;
	}

	ret = nfs_callback_up_net(minorversion, serv, net);
	if (ret < 0)
		goto err_net;

	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	if (ret < 0)
		goto err_start;

	cb_info->users++;
	/*
	 * 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.
	 */
err_net:
	svc_destroy(serv);
err_create:
	mutex_unlock(&nfs_callback_mutex);
	return ret;

err_start:
	nfs_callback_down_net(minorversion, serv, net);
	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
	goto err_net;
}

/*
 * Kill the callback thread if it's no longer being used.
 */
void nfs_callback_down(int minorversion, struct net *net)
{
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];

	mutex_lock(&nfs_callback_mutex);
	nfs_callback_down_net(minorversion, cb_info->serv, net);
	cb_info->users--;
	if (cb_info->users == 0 && cb_info->task != NULL) {
		kthread_stop(cb_info->task);
		dprintk("nfs_callback_down: service stopped\n");
		svc_exit_thread(cb_info->rqst);
		dprintk("nfs_callback_down: service destroyed\n");
		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>
758201e2	15	#include <linux/errno.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	20	#include <linux/sunrpc/bc_xprt.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"
bbe0a3aa	27	#include "netns.h"
1da177e4 LT	28
	29	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	30
	31	struct nfs_callback_data {
	32	unsigned int users;
a43cde94	33	struct svc_serv *serv;
5afc597c	34	struct svc_rqst *rqst;
a277e33c	35	struct task_struct *task;
1da177e4 LT	36	};
1da177e4 LT	37
e82dc22d	38	static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
353ab6e9	39	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	40	static struct svc_program nfs4_callback_program;
1da177e4 LT	41
c946556b SK	42	static int nfs4_callback_up_net(struct svc_serv serv, struct net net)
	43	{
	44	int ret;
bbe0a3aa	45	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	46
	47	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
	48	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	49	if (ret <= 0)
	50	goto out_err;
bbe0a3aa	51	nn->nfs_callback_tcpport = ret;
c946556b	52	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
bbe0a3aa	53	nn->nfs_callback_tcpport, PF_INET, net);
c946556b SK	54
	55	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
	56	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	57	if (ret > 0) {
29dcc16a	58	nn->nfs_callback_tcpport6 = ret;
c946556b	59	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
29dcc16a	60	nn->nfs_callback_tcpport6, PF_INET6, net);
c946556b SK	61	} else if (ret != -EAFNOSUPPORT)
	62	goto out_err;
	63	return 0;
	64
	65	out_err:
	66	return (ret) ? ret : -ENOMEM;
	67	}
	68
1da177e4	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	{
5b444cc9	75	int err;
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);
5b444cc9	85	if (err == -EAGAIN \|\| err == -EINTR)
1da177e4	86	continue;
6fb2b47f	87	svc_process(rqstp);
1da177e4	88	}
a277e33c	89	return 0;
1da177e4 LT	90	}
	91
	92	/*
71468513	93	* Prepare to bring up the NFSv4 callback service
1da177e4	94	*/
17280175	95	static struct svc_rqst *
691c457a	96	nfs4_callback_up(struct svc_serv *serv)
1da177e4	97	{
11fd165c	98	return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
71468513 BH	99	}
71468513 BH	100
a43cde94	101	#if defined(CONFIG_NFS_V4_1)
c946556b SK	102	static int nfs41_callback_up_net(struct svc_serv serv, struct net net)
	103	{
	104	/*
	105	* Create an svc_sock for the back channel service that shares the
	106	* fore channel connection.
	107	* Returns the input port (0) and sets the svc_serv bc_xprt on success
	108	*/
	109	return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
	110	SVC_SOCK_ANONYMOUS);
	111	}
	112
a43cde94 RL	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	127	while (!kthread_should_stop()) {
25d280aa JL	128	if (try_to_freeze())
	129	continue;
	130
a43cde94 RL	131	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	132	spin_lock_bh(&serv->sv_cb_lock);
	133	if (!list_empty(&serv->sv_cb_list)) {
	134	req = list_first_entry(&serv->sv_cb_list,
	135	struct rpc_rqst, rq_bc_list);
	136	list_del(&req->rq_bc_list);
	137	spin_unlock_bh(&serv->sv_cb_lock);
	138	dprintk("Invoking bc_svc_process()\n");
	139	error = bc_svc_process(serv, req, rqstp);
	140	dprintk("bc_svc_process() returned w/ error code= %d\n",
	141	error);
	142	} else {
	143	spin_unlock_bh(&serv->sv_cb_lock);
	144	schedule();
	145	}
	146	finish_wait(&serv->sv_cb_waitq, &wq);
	147	}
a43cde94 RL	148	return 0;
	149	}
	150
	151	/*
	152	* Bring up the NFSv4.1 callback service
	153	*/
17280175	154	static struct svc_rqst *
691c457a	155	nfs41_callback_up(struct svc_serv *serv)
a43cde94	156	{
01c9a0bc	157	struct svc_rqst *rqstp;
8f975242	158
a43cde94 RL	159	INIT_LIST_HEAD(&serv->sv_cb_list);
	160	spin_lock_init(&serv->sv_cb_lock);
	161	init_waitqueue_head(&serv->sv_cb_waitq);
11fd165c	162	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
01c9a0bc	163	if (IS_ERR(rqstp)) {
4a19de0f AA	164	svc_xprt_put(serv->sv_bc_xprt);
4a19de0f AA	165	serv->sv_bc_xprt = NULL;
01c9a0bc	166	}
54bcfa66	167	dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
8f975242	168	return rqstp;
a43cde94 RL	169	}
a43cde94 RL	170
758201e2	171	static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
a43cde94 RL	172	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
a43cde94 RL	173	{
758201e2 TM	174	*rqstpp = nfs41_callback_up(serv);
758201e2 TM	175	*callback_svc = nfs41_callback_svc;
a43cde94 RL	176	}
	177
	178	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	179	struct svc_serv *serv)
a43cde94 RL	180	{
a43cde94 RL	181	if (minorversion)
691c457a SK	182	/*
	183	* Save the svc_serv in the transport so that it can
	184	* be referenced when the session backchannel is initialized
	185	*/
	186	xprt->bc_serv = serv;
a43cde94 RL	187	}
a43cde94 RL	188	#else
c946556b SK	189	static int nfs41_callback_up_net(struct svc_serv serv, struct net net)
	190	{
	191	return 0;
	192	}
	193
758201e2	194	static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
a43cde94 RL	195	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
a43cde94 RL	196	{
758201e2 TM	197	*rqstpp = ERR_PTR(-ENOTSUPP);
758201e2 TM	198	*callback_svc = ERR_PTR(-ENOTSUPP);
a43cde94 RL	199	}
	200
	201	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	202	struct svc_serv *serv)
a43cde94 RL	203	{
	204	}
	205	#endif /* CONFIG_NFS_V4_1 */
	206
8e246144 SK	207	static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
	208	struct svc_serv *serv)
	209	{
	210	struct svc_rqst *rqstp;
	211	int (callback_svc)(void vrqstp);
	212	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
8e246144	213	int ret;
8e246144 SK	214
	215	nfs_callback_bc_serv(minorversion, xprt, serv);
	216
23c20ecd SK	217	if (cb_info->task)
	218	return 0;
	219
758201e2 TM	220	switch (minorversion) {
758201e2 TM	221	case 0:
8e246144 SK	222	/* v4.0 callback setup */
	223	rqstp = nfs4_callback_up(serv);
	224	callback_svc = nfs4_callback_svc;
758201e2 TM	225	break;
	226	default:
	227	nfs_minorversion_callback_svc_setup(serv,
	228	&rqstp, &callback_svc);
8e246144 SK	229	}
	230
	231	if (IS_ERR(rqstp))
	232	return PTR_ERR(rqstp);
	233
	234	svc_sock_update_bufs(serv);
	235
8e246144 SK	236	cb_info->serv = serv;
8e246144 SK	237	cb_info->rqst = rqstp;
f170168b KC	238	cb_info->task = kthread_run(callback_svc, cb_info->rqst,
f170168b KC	239	"nfsv4.%u-svc", minorversion);
8e246144 SK	240	if (IS_ERR(cb_info->task)) {
	241	ret = PTR_ERR(cb_info->task);
	242	svc_exit_thread(cb_info->rqst);
	243	cb_info->rqst = NULL;
	244	cb_info->task = NULL;
e9b7e917	245	return ret;
8e246144 SK	246	}
	247	dprintk("nfs_callback_up: service started\n");
	248	return 0;
	249	}
	250
b3d19c51 SK	251	static void nfs_callback_down_net(u32 minorversion, struct svc_serv serv, struct net net)
	252	{
	253	struct nfs_net *nn = net_generic(net, nfs_net_id);
	254
	255	if (--nn->cb_users[minorversion])
	256	return;
	257
	258	dprintk("NFS: destroy per-net callback data; net=%p\n", net);
	259	svc_shutdown_net(serv, net);
	260	}
	261
c946556b SK	262	static int nfs_callback_up_net(int minorversion, struct svc_serv serv, struct net net)
c946556b SK	263	{
b3d19c51	264	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	265	int ret;
c946556b SK	266
b3d19c51 SK	267	if (nn->cb_users[minorversion]++)
	268	return 0;
	269
c946556b SK	270	dprintk("NFS: create per-net callback data; net=%p\n", net);
	271
	272	ret = svc_bind(serv, net);
	273	if (ret < 0) {
	274	printk(KERN_WARNING "NFS: bind callback service failed\n");
	275	goto err_bind;
	276	}
	277
	278	switch (minorversion) {
	279	case 0:
	280	ret = nfs4_callback_up_net(serv, net);
	281	break;
	282	case 1:
42c2c424	283	case 2:
c946556b SK	284	ret = nfs41_callback_up_net(serv, net);
	285	break;
	286	default:
	287	printk(KERN_ERR "NFS: unknown callback version: %d\n",
	288	minorversion);
	289	ret = -EINVAL;
	290	break;
	291	}
	292
	293	if (ret < 0) {
	294	printk(KERN_ERR "NFS: callback service start failed\n");
	295	goto err_socks;
	296	}
	297	return 0;
	298
	299	err_socks:
	300	svc_rpcb_cleanup(serv, net);
	301	err_bind:
23c20ecd SK	302	dprintk("NFS: Couldn't create callback socket: err = %d; "
23c20ecd SK	303	"net = %p\n", ret, net);
c946556b SK	304	return ret;
	305	}
	306
dd018428 SK	307	static struct svc_serv *nfs_callback_create_svc(int minorversion)
	308	{
	309	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	310	struct svc_serv *serv;
	311
	312	/*
	313	* Check whether we're already up and running.
	314	*/
	315	if (cb_info->task) {
	316	/*
	317	* Note: increase service usage, because later in case of error
	318	* svc_destroy() will be called.
	319	*/
	320	svc_get(cb_info->serv);
	321	return cb_info->serv;
	322	}
	323
	324	/*
	325	* Sanity check: if there's no task,
	326	* we should be the first user ...
	327	*/
	328	if (cb_info->users)
	329	printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
	330	cb_info->users);
	331
	332	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	333	if (!serv) {
	334	printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
	335	return ERR_PTR(-ENOMEM);
	336	}
	337	/* As there is only one thread we need to over-ride the
	338	* default maximum of 80 connections
	339	*/
	340	serv->sv_maxconn = 1024;
	341	dprintk("nfs_callback_create_svc: service created\n");
	342	return serv;
	343	}
	344
71468513 BH	345	/*
	346	* Bring up the callback thread if it is not already up.
	347	*/
	348	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	349	{
dd018428	350	struct svc_serv *serv;
e82dc22d	351	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
23c20ecd	352	int ret;
c946556b	353	struct net *net = xprt->xprt_net;
71468513 BH	354
71468513 BH	355	mutex_lock(&nfs_callback_mutex);
dd018428 SK	356
	357	serv = nfs_callback_create_svc(minorversion);
	358	if (IS_ERR(serv)) {
	359	ret = PTR_ERR(serv);
	360	goto err_create;
	361	}
	362
c946556b SK	363	ret = nfs_callback_up_net(minorversion, serv, net);
	364	if (ret < 0)
	365	goto err_net;
9793f7c8	366
8e246144 SK	367	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	368	if (ret < 0)
	369	goto err_start;
a277e33c	370
23c20ecd	371	cb_info->users++;
8e60029f JL	372	/*
8e60029f JL	373	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	374	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	375	* on both success and failure so that the refcount is 1 when the
	376	* thread exits.
	377	*/
23c20ecd	378	err_net:
dd018428 SK	379	svc_destroy(serv);
dd018428 SK	380	err_create:
353ab6e9	381	mutex_unlock(&nfs_callback_mutex);
1da177e4	382	return ret;
8e246144 SK	383
8e246144 SK	384	err_start:
b3d19c51	385	nfs_callback_down_net(minorversion, serv, net);
23c20ecd SK	386	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
23c20ecd SK	387	goto err_net;
1da177e4 LT	388	}
	389
	390	/*
5afc597c	391	* Kill the callback thread if it's no longer being used.
1da177e4	392	*/
c8ceb412	393	void nfs_callback_down(int minorversion, struct net *net)
1da177e4	394	{
e82dc22d AA	395	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	396
353ab6e9	397	mutex_lock(&nfs_callback_mutex);
b3d19c51	398	nfs_callback_down_net(minorversion, cb_info->serv, net);
e82dc22d AA	399	cb_info->users--;
	400	if (cb_info->users == 0 && cb_info->task != NULL) {
	401	kthread_stop(cb_info->task);
1dc42e04	402	dprintk("nfs_callback_down: service stopped\n");
e82dc22d	403	svc_exit_thread(cb_info->rqst);
1dc42e04	404	dprintk("nfs_callback_down: service destroyed\n");
e82dc22d AA	405	cb_info->serv = NULL;
	406	cb_info->rqst = NULL;
	407	cb_info->task = NULL;
5afc597c	408	}
353ab6e9	409	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	410	}
1da177e4 LT	411
778be232 AA	412	/* Boolean check of RPC_AUTH_GSS principal */
	413	int
	414	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	415	{
03a4e1f6	416	char *p = rqstp->rq_cred.cr_principal;
945b34a7	417
778be232 AA	418	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	419	return 1;
	420
ece0de63 AA	421	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	422	if (clp->cl_minorversion != 0)
778be232	423	return 0;
945b34a7 OK	424	/*
	425	* It might just be a normal user principal, in which case
	426	* userspace won't bother to tell us the name at all.
	427	*/
	428	if (p == NULL)
778be232	429	return 0;
945b34a7 OK	430
	431	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	432
	433	if (memcmp(p, "nfs@", 4) != 0)
778be232	434	return 0;
945b34a7	435	p += 4;
4e0038b6	436	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	437	return 0;
778be232 AA	438	return 1;
945b34a7 OK	439	}
945b34a7 OK	440
778be232 AA	441	/*
	442	* pg_authenticate method for nfsv4 callback threads.
	443	*
	444	* The authflavor has been negotiated, so an incorrect flavor is a server
	445	* bug. Drop packets with incorrect authflavor.
	446	*
	447	* All other checking done after NFS decoding where the nfs_client can be
	448	* found in nfs4_callback_compound
	449	*/
1da177e4 LT	450	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	451	{
1da177e4	452	switch (rqstp->rq_authop->flavour) {
778be232 AA	453	case RPC_AUTH_NULL:
	454	if (rqstp->rq_proc != CB_NULL)
	455	return SVC_DROP;
	456	break;
	457	case RPC_AUTH_GSS:
	458	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	459	if (svc_is_backchannel(rqstp))
	460	return SVC_DROP;
1da177e4	461	}
778be232	462	return SVC_OK;
1da177e4 LT	463	}
	464
	465	/*
	466	* Define NFS4 callback program
	467	*/
1da177e4 LT	468	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	469	[1] = &nfs4_callback_version1,
07bccc2d	470	[4] = &nfs4_callback_version4,
1da177e4 LT	471	};
	472
	473	static struct svc_stat nfs4_callback_stats;
	474
	475	static struct svc_program nfs4_callback_program = {
	476	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	477	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	478	.pg_vers = nfs4_callback_version, /* version table */
	479	.pg_name = "NFSv4 callback", /* service name */
	480	.pg_class = "nfs", /* authentication class */
	481	.pg_stats = &nfs4_callback_stats,
	482	.pg_authenticate = nfs_callback_authenticate,
	483	};