[linux-block.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 <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)
/*
 *  * CB_SEQUENCE operations will fail until the callback sessionid is set.
 *   */
int nfs4_set_callback_sessionid(struct nfs_client *clp)
{
	struct svc_serv *serv = clp->cl_rpcclient->cl_xprt->bc_serv;
	struct nfs4_sessionid *bc_sid;

	if (!serv->bc_xprt)
		return -EINVAL;

	/* on success freed in xprt_free */
	bc_sid = kmalloc(sizeof(struct nfs4_sessionid), GFP_KERNEL);
	if (!bc_sid)
		return -ENOMEM;
	memcpy(bc_sid->data, &clp->cl_session->sess_id.data,
		NFS4_MAX_SESSIONID_LEN);
	spin_lock_bh(&serv->sv_cb_lock);
	serv->bc_xprt->xpt_bc_sid = bc_sid;
	spin_unlock_bh(&serv->sv_cb_lock);
	dprintk("%s set xpt_bc_sid=%u:%u:%u:%u for bc_xprt %p\n", __func__,
		((u32 *)bc_sid->data)[0], ((u32 *)bc_sid->data)[1],
		((u32 *)bc_sid->data)[2], ((u32 *)bc_sid->data)[3],
		serv->bc_xprt);
	return 0;
}

/*
 * 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_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", &init_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]);
	if (IS_ERR(rqstp)) {
		svc_xprt_put(serv->bc_xprt);
		serv->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)
{
}
int nfs4_set_callback_sessionid(struct nfs_client *clp)
{
	return 0;
}
#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);

	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
	if (clp->cl_minorversion != 0)
		return SVC_DROP;
	/*
	 * 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;
}

/* pg_authenticate method helper */
static struct nfs_client *nfs_cb_find_client(struct svc_rqst *rqstp)
{
	struct nfs4_sessionid *sessionid = bc_xprt_sid(rqstp);
	int is_cb_compound = rqstp->rq_proc == CB_COMPOUND ? 1 : 0;

	dprintk("--> %s rq_proc %d\n", __func__, rqstp->rq_proc);
	if (svc_is_backchannel(rqstp))
		/* Sessionid (usually) set after CB_NULL ping */
		return nfs4_find_client_sessionid(svc_addr(rqstp), sessionid,
						  is_cb_compound);
	else
		/* No callback identifier in pg_authenticate */
		return nfs4_find_client_no_ident(svc_addr(rqstp));
}

/* pg_authenticate method for nfsv4 callback threads. */
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_cb_find_client(rqstp);
	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>
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>
14c85021 ACM	20
	21	#include <net/inet_sock.h>
	22
4ce79717	23	#include "nfs4_fs.h"
1da177e4	24	#include "callback.h"
24c8dbbb	25	#include "internal.h"
1da177e4 LT	26
	27	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	28
	29	struct nfs_callback_data {
	30	unsigned int users;
a43cde94	31	struct svc_serv *serv;
5afc597c	32	struct svc_rqst *rqst;
a277e33c	33	struct task_struct *task;
1da177e4 LT	34	};
1da177e4 LT	35
e82dc22d	36	static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
353ab6e9	37	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	38	static struct svc_program nfs4_callback_program;
1da177e4 LT	39
a72b4422	40	unsigned int nfs_callback_set_tcpport;
1da177e4	41	unsigned short nfs_callback_tcpport;
f738f517	42	unsigned short nfs_callback_tcpport6;
c140aa91	43	#define NFS_CALLBACK_MAXPORTNR (65535U)
7d4e2747	44
9bbb9e5a	45	static int param_set_portnr(const char val, const struct kernel_param kp)
7d4e2747	46	{
c140aa91 TM	47	unsigned long num;
	48	int ret;
	49
	50	if (!val)
	51	return -EINVAL;
	52	ret = strict_strtoul(val, 0, &num);
	53	if (ret == -EINVAL \|\| num > NFS_CALLBACK_MAXPORTNR)
7d4e2747	54	return -EINVAL;
c140aa91	55	((unsigned int )kp->arg) = num;
7d4e2747 DH	56	return 0;
7d4e2747 DH	57	}
9bbb9e5a RR	58	static struct kernel_param_ops param_ops_portnr = {
	59	.set = param_set_portnr,
	60	.get = param_get_uint,
	61	};
c140aa91 TM	62	#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
	63
	64	module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1da177e4 LT	65
1da177e4 LT	66	/*
e82dc22d	67	* This is the NFSv4 callback kernel thread.
1da177e4	68	*/
a277e33c	69	static int
71468513	70	nfs4_callback_svc(void *vrqstp)
1da177e4	71	{
06e02d66	72	int err, preverr = 0;
a277e33c	73	struct svc_rqst *rqstp = vrqstp;
1da177e4	74
83144186	75	set_freezable();
1da177e4	76
a277e33c	77	while (!kthread_should_stop()) {
1da177e4 LT	78	/*
	79	* Listen for a request on the socket
	80	*/
6fb2b47f	81	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
06e02d66 JL	82	if (err == -EAGAIN \|\| err == -EINTR) {
06e02d66 JL	83	preverr = err;
1da177e4	84	continue;
06e02d66	85	}
1da177e4	86	if (err < 0) {
06e02d66 JL	87	if (err != preverr) {
	88	printk(KERN_WARNING "%s: unexpected error "
	89	"from svc_recv (%d)\n", __func__, err);
	90	preverr = err;
	91	}
	92	schedule_timeout_uninterruptible(HZ);
	93	continue;
1da177e4	94	}
06e02d66	95	preverr = err;
6fb2b47f	96	svc_process(rqstp);
1da177e4	97	}
a277e33c	98	return 0;
1da177e4 LT	99	}
	100
	101	/*
71468513	102	* Prepare to bring up the NFSv4 callback service
1da177e4	103	*/
71468513 BH	104	struct svc_rqst *
71468513 BH	105	nfs4_callback_up(struct svc_serv *serv)
1da177e4	106	{
71468513	107	int ret;
482fb94e	108
fc5d00b0	109	ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET,
9652ada3	110	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
482fb94e	111	if (ret <= 0)
8e60029f	112	goto out_err;
482fb94e	113	nfs_callback_tcpport = ret;
18de9735	114	dprintk("NFS: Callback listener port = %u (af %u)\n",
26298caa	115	nfs_callback_tcpport, PF_INET);
482fb94e	116
fc5d00b0	117	ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET6,
f738f517 CL	118	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	119	if (ret > 0) {
	120	nfs_callback_tcpport6 = ret;
	121	dprintk("NFS: Callback listener port = %u (af %u)\n",
	122	nfs_callback_tcpport6, PF_INET6);
18fc3164 CL	123	} else if (ret == -EAFNOSUPPORT)
	124	ret = 0;
	125	else
f738f517	126	goto out_err;
f738f517	127
71468513 BH	128	return svc_prepare_thread(serv, &serv->sv_pools[0]);
	129
	130	out_err:
	131	if (ret == 0)
	132	ret = -ENOMEM;
	133	return ERR_PTR(ret);
	134	}
	135
a43cde94	136	#if defined(CONFIG_NFS_V4_1)
2c2618c6 AA	137	/*
	138	* * CB_SEQUENCE operations will fail until the callback sessionid is set.
	139	* */
	140	int nfs4_set_callback_sessionid(struct nfs_client *clp)
	141	{
	142	struct svc_serv *serv = clp->cl_rpcclient->cl_xprt->bc_serv;
	143	struct nfs4_sessionid *bc_sid;
	144
	145	if (!serv->bc_xprt)
	146	return -EINVAL;
	147
	148	/* on success freed in xprt_free */
	149	bc_sid = kmalloc(sizeof(struct nfs4_sessionid), GFP_KERNEL);
	150	if (!bc_sid)
	151	return -ENOMEM;
	152	memcpy(bc_sid->data, &clp->cl_session->sess_id.data,
	153	NFS4_MAX_SESSIONID_LEN);
	154	spin_lock_bh(&serv->sv_cb_lock);
	155	serv->bc_xprt->xpt_bc_sid = bc_sid;
	156	spin_unlock_bh(&serv->sv_cb_lock);
	157	dprintk("%s set xpt_bc_sid=%u:%u:%u:%u for bc_xprt %p\n", __func__,
	158	((u32 )bc_sid->data)[0], ((u32 )bc_sid->data)[1],
	159	((u32 )bc_sid->data)[2], ((u32 )bc_sid->data)[3],
	160	serv->bc_xprt);
	161	return 0;
	162	}
	163
a43cde94 RL	164	/*
	165	* The callback service for NFSv4.1 callbacks
	166	*/
	167	static int
	168	nfs41_callback_svc(void *vrqstp)
	169	{
	170	struct svc_rqst *rqstp = vrqstp;
	171	struct svc_serv *serv = rqstp->rq_server;
	172	struct rpc_rqst *req;
	173	int error;
	174	DEFINE_WAIT(wq);
	175
	176	set_freezable();
	177
a43cde94 RL	178	while (!kthread_should_stop()) {
	179	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
	180	spin_lock_bh(&serv->sv_cb_lock);
	181	if (!list_empty(&serv->sv_cb_list)) {
	182	req = list_first_entry(&serv->sv_cb_list,
	183	struct rpc_rqst, rq_bc_list);
	184	list_del(&req->rq_bc_list);
	185	spin_unlock_bh(&serv->sv_cb_lock);
	186	dprintk("Invoking bc_svc_process()\n");
	187	error = bc_svc_process(serv, req, rqstp);
	188	dprintk("bc_svc_process() returned w/ error code= %d\n",
	189	error);
	190	} else {
	191	spin_unlock_bh(&serv->sv_cb_lock);
	192	schedule();
	193	}
	194	finish_wait(&serv->sv_cb_waitq, &wq);
	195	}
a43cde94 RL	196	return 0;
	197	}
	198
	199	/*
	200	* Bring up the NFSv4.1 callback service
	201	*/
	202	struct svc_rqst *
	203	nfs41_callback_up(struct svc_serv serv, struct rpc_xprt xprt)
	204	{
01c9a0bc AA	205	struct svc_rqst *rqstp;
01c9a0bc AA	206	int ret;
8f975242	207
01c9a0bc AA	208	/*
	209	* Create an svc_sock for the back channel service that shares the
	210	* fore channel connection.
	211	* Returns the input port (0) and sets the svc_serv bc_xprt on success
	212	*/
	213	ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0,
	214	SVC_SOCK_ANONYMOUS);
	215	if (ret < 0) {
	216	rqstp = ERR_PTR(ret);
8f975242	217	goto out;
01c9a0bc	218	}
8f975242	219
a43cde94 RL	220	/*
	221	* Save the svc_serv in the transport so that it can
	222	* be referenced when the session backchannel is initialized
	223	*/
	224	xprt->bc_serv = serv;
	225
	226	INIT_LIST_HEAD(&serv->sv_cb_list);
	227	spin_lock_init(&serv->sv_cb_lock);
	228	init_waitqueue_head(&serv->sv_cb_waitq);
8f975242	229	rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
01c9a0bc AA	230	if (IS_ERR(rqstp)) {
	231	svc_xprt_put(serv->bc_xprt);
	232	serv->bc_xprt = NULL;
	233	}
8f975242	234	out:
01c9a0bc AA	235	dprintk("--> %s return %ld\n", __func__,
01c9a0bc AA	236	IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
8f975242	237	return rqstp;
a43cde94 RL	238	}
	239
	240	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	241	struct svc_serv serv, struct rpc_xprt xprt,
	242	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	243	{
	244	if (minorversion) {
	245	*rqstpp = nfs41_callback_up(serv, xprt);
	246	*callback_svc = nfs41_callback_svc;
	247	}
	248	return minorversion;
	249	}
	250
	251	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	252	struct nfs_callback_data *cb_info)
	253	{
	254	if (minorversion)
	255	xprt->bc_serv = cb_info->serv;
	256	}
	257	#else
	258	static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
	259	struct svc_serv serv, struct rpc_xprt xprt,
	260	struct svc_rqst rqstpp, int (callback_svc)(void *vrqstp))
	261	{
	262	return 0;
	263	}
	264
	265	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
	266	struct nfs_callback_data *cb_info)
	267	{
	268	}
2c2618c6 AA	269	int nfs4_set_callback_sessionid(struct nfs_client *clp)
	270	{
	271	return 0;
	272	}
a43cde94 RL	273	#endif /* CONFIG_NFS_V4_1 */
a43cde94 RL	274
71468513 BH	275	/*
	276	* Bring up the callback thread if it is not already up.
	277	*/
	278	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	279	{
	280	struct svc_serv *serv = NULL;
	281	struct svc_rqst *rqstp;
	282	int (callback_svc)(void vrqstp);
e82dc22d	283	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
71468513 BH	284	char svc_name[12];
71468513 BH	285	int ret = 0;
a43cde94	286	int minorversion_setup;
71468513 BH	287
71468513 BH	288	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	289	if (cb_info->users++ \|\| cb_info->task != NULL) {
e82dc22d AA	290	nfs_callback_bc_serv(minorversion, xprt, cb_info);
71468513	291	goto out;
a43cde94	292	}
71468513 BH	293	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	294	if (!serv) {
	295	ret = -ENOMEM;
	296	goto out_err;
	297	}
	298
a43cde94 RL	299	minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
	300	serv, xprt, &rqstp, &callback_svc);
	301	if (!minorversion_setup) {
	302	/* v4.0 callback setup */
71468513 BH	303	rqstp = nfs4_callback_up(serv);
71468513 BH	304	callback_svc = nfs4_callback_svc;
71468513 BH	305	}
	306
	307	if (IS_ERR(rqstp)) {
	308	ret = PTR_ERR(rqstp);
8e60029f	309	goto out_err;
a277e33c JL	310	}
	311
	312	svc_sock_update_bufs(serv);
a277e33c	313
71468513	314	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
e82dc22d AA	315	cb_info->serv = serv;
	316	cb_info->rqst = rqstp;
	317	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
	318	if (IS_ERR(cb_info->task)) {
	319	ret = PTR_ERR(cb_info->task);
	320	svc_exit_thread(cb_info->rqst);
	321	cb_info->rqst = NULL;
	322	cb_info->task = NULL;
a277e33c JL	323	goto out_err;
a277e33c JL	324	}
1da177e4	325	out:
8e60029f JL	326	/*
8e60029f JL	327	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	328	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	329	* on both success and failure so that the refcount is 1 when the
	330	* thread exits.
	331	*/
	332	if (serv)
	333	svc_destroy(serv);
353ab6e9	334	mutex_unlock(&nfs_callback_mutex);
1da177e4	335	return ret;
8e60029f	336	out_err:
18de9735 CL	337	dprintk("NFS: Couldn't create callback socket or server thread; "
18de9735 CL	338	"err = %d\n", ret);
e82dc22d	339	cb_info->users--;
1da177e4 LT	340	goto out;
	341	}
	342
	343	/*
5afc597c	344	* Kill the callback thread if it's no longer being used.
1da177e4	345	*/
e82dc22d	346	void nfs_callback_down(int minorversion)
1da177e4	347	{
e82dc22d AA	348	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
e82dc22d AA	349
353ab6e9	350	mutex_lock(&nfs_callback_mutex);
e82dc22d AA	351	cb_info->users--;
	352	if (cb_info->users == 0 && cb_info->task != NULL) {
	353	kthread_stop(cb_info->task);
	354	svc_exit_thread(cb_info->rqst);
	355	cb_info->serv = NULL;
	356	cb_info->rqst = NULL;
	357	cb_info->task = NULL;
5afc597c	358	}
353ab6e9	359	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	360	}
1da177e4 LT	361
945b34a7 OK	362	static int check_gss_callback_principal(struct nfs_client *clp,
	363	struct svc_rqst *rqstp)
	364	{
	365	struct rpc_clnt *r = clp->cl_rpcclient;
	366	char *p = svc_gss_principal(rqstp);
	367
ece0de63 AA	368	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
	369	if (clp->cl_minorversion != 0)
	370	return SVC_DROP;
945b34a7 OK	371	/*
	372	* It might just be a normal user principal, in which case
	373	* userspace won't bother to tell us the name at all.
	374	*/
	375	if (p == NULL)
	376	return SVC_DENIED;
	377
	378	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	379
	380	if (memcmp(p, "nfs@", 4) != 0)
	381	return SVC_DENIED;
	382	p += 4;
	383	if (strcmp(p, r->cl_server) != 0)
	384	return SVC_DENIED;
	385	return SVC_OK;
	386	}
	387
c36fca52 AA	388	/* pg_authenticate method helper */
	389	static struct nfs_client nfs_cb_find_client(struct svc_rqst rqstp)
	390	{
	391	struct nfs4_sessionid *sessionid = bc_xprt_sid(rqstp);
	392	int is_cb_compound = rqstp->rq_proc == CB_COMPOUND ? 1 : 0;
	393
	394	dprintk("--> %s rq_proc %d\n", __func__, rqstp->rq_proc);
	395	if (svc_is_backchannel(rqstp))
	396	/* Sessionid (usually) set after CB_NULL ping */
	397	return nfs4_find_client_sessionid(svc_addr(rqstp), sessionid,
	398	is_cb_compound);
	399	else
	400	/* No callback identifier in pg_authenticate */
	401	return nfs4_find_client_no_ident(svc_addr(rqstp));
	402	}
	403
	404	/* pg_authenticate method for nfsv4 callback threads. */
1da177e4 LT	405	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	406	{
adfa6f98	407	struct nfs_client *clp;
5216a8e7	408	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
945b34a7	409	int ret = SVC_OK;
1da177e4 LT	410
1da177e4 LT	411	/* Don't talk to strangers */
c36fca52	412	clp = nfs_cb_find_client(rqstp);
1da177e4 LT	413	if (clp == NULL)
1da177e4 LT	414	return SVC_DROP;
ad06e4bd	415
3110ff80	416	dprintk("%s: %s NFSv4 callback!\n", __func__,
ad06e4bd	417	svc_print_addr(rqstp, buf, sizeof(buf)));
ad06e4bd	418
1da177e4 LT	419	switch (rqstp->rq_authop->flavour) {
	420	case RPC_AUTH_NULL:
	421	if (rqstp->rq_proc != CB_NULL)
945b34a7	422	ret = SVC_DENIED;
1da177e4 LT	423	break;
	424	case RPC_AUTH_UNIX:
	425	break;
	426	case RPC_AUTH_GSS:
945b34a7 OK	427	ret = check_gss_callback_principal(clp, rqstp);
945b34a7 OK	428	break;
1da177e4	429	default:
945b34a7	430	ret = SVC_DENIED;
1da177e4	431	}
945b34a7 OK	432	nfs_put_client(clp);
945b34a7 OK	433	return ret;
1da177e4 LT	434	}
	435
	436	/*
	437	* Define NFS4 callback program
	438	*/
1da177e4 LT	439	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	440	[1] = &nfs4_callback_version1,
07bccc2d	441	[4] = &nfs4_callback_version4,
1da177e4 LT	442	};
	443
	444	static struct svc_stat nfs4_callback_stats;
	445
	446	static struct svc_program nfs4_callback_program = {
	447	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	448	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	449	.pg_vers = nfs4_callback_version, /* version table */
	450	.pg_name = "NFSv4 callback", /* service name */
	451	.pg_class = "nfs", /* authentication class */
	452	.pg_stats = &nfs4_callback_stats,
	453	.pg_authenticate = nfs_callback_authenticate,
	454	};