[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 <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;
	pid_t pid;
	struct completion started;
	struct completion stopped;
};

static struct nfs_callback_data nfs_callback_info;
static DEFINE_MUTEX(nfs_callback_mutex);
static struct svc_program nfs4_callback_program;

unsigned int nfs_callback_set_tcpport;
unsigned short nfs_callback_tcpport;
static const int nfs_set_port_min = 0;
static const int nfs_set_port_max = 65535;

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

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

/*
 * This is the callback kernel thread.
 */
static void nfs_callback_svc(struct svc_rqst *rqstp)
{
	int err;

	__module_get(THIS_MODULE);
	lock_kernel();

	nfs_callback_info.pid = current->pid;
	daemonize("nfsv4-svc");
	/* Process request with signals blocked, but allow SIGKILL.  */
	allow_signal(SIGKILL);
	set_freezable();

	complete(&nfs_callback_info.started);

	for(;;) {
		if (signalled()) {
			if (nfs_callback_info.users == 0)
				break;
			flush_signals(current);
		}
		/*
		 * Listen for a request on the socket
		 */
		err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
		if (err == -EAGAIN || err == -EINTR)
			continue;
		if (err < 0) {
			printk(KERN_WARNING
					"%s: terminating on error %d\n",
					__FUNCTION__, -err);
			break;
		}
		svc_process(rqstp);
	}

	svc_exit_thread(rqstp);
	nfs_callback_info.pid = 0;
	complete(&nfs_callback_info.stopped);
	unlock_kernel();
	module_put_and_exit(0);
}

/*
 * Bring up the server process if it is not already up.
 */
int nfs_callback_up(void)
{
	struct svc_serv *serv;
	int ret = 0;

	lock_kernel();
	mutex_lock(&nfs_callback_mutex);
	if (nfs_callback_info.users++ || nfs_callback_info.pid != 0)
		goto out;
	init_completion(&nfs_callback_info.started);
	init_completion(&nfs_callback_info.stopped);
	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
	ret = -ENOMEM;
	if (!serv)
		goto out_err;

	ret = svc_create_xprt(serv, "tcp", nfs_callback_set_tcpport,
			      SVC_SOCK_ANONYMOUS);
	if (ret <= 0)
		goto out_destroy;
	nfs_callback_tcpport = ret;
	dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);

	ret = svc_create_thread(nfs_callback_svc, serv);
	if (ret < 0)
		goto out_destroy;
	nfs_callback_info.serv = serv;
	wait_for_completion(&nfs_callback_info.started);
out:
	mutex_unlock(&nfs_callback_mutex);
	unlock_kernel();
	return ret;
out_destroy:
	dprintk("Couldn't create callback socket or server thread; err = %d\n",
		ret);
	svc_destroy(serv);
out_err:
	nfs_callback_info.users--;
	goto out;
}

/*
 * Kill the server process if it is not already up.
 */
void nfs_callback_down(void)
{
	lock_kernel();
	mutex_lock(&nfs_callback_mutex);
	nfs_callback_info.users--;
	do {
		if (nfs_callback_info.users != 0 || nfs_callback_info.pid == 0)
			break;
		if (kill_proc(nfs_callback_info.pid, SIGKILL, 1) < 0)
			break;
	} while (wait_for_completion_timeout(&nfs_callback_info.stopped, 5*HZ) == 0);
	mutex_unlock(&nfs_callback_mutex);
	unlock_kernel();
}

static int nfs_callback_authenticate(struct svc_rqst *rqstp)
{
	struct nfs_client *clp;
	char buf[RPC_MAX_ADDRBUFLEN];

	/* 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", __FUNCTION__,
			svc_print_addr(rqstp, buf, sizeof(buf)));
	nfs_put_client(clp);

	switch (rqstp->rq_authop->flavour) {
		case RPC_AUTH_NULL:
			if (rqstp->rq_proc != CB_NULL)
				return SVC_DENIED;
			break;
		case RPC_AUTH_UNIX:
			break;
		case RPC_AUTH_GSS:
			/* FIXME: RPCSEC_GSS handling? */
		default:
			return SVC_DENIED;
	}
	return SVC_OK;
}

/*
 * Define NFS4 callback program
 */
static struct svc_version *nfs4_callback_version[] = {
	[1] = &nfs4_callback_version1,
};

static struct svc_stat nfs4_callback_stats;

static struct svc_program nfs4_callback_program = {
	.pg_prog = NFS4_CALLBACK,			/* RPC service number */
	.pg_nvers = ARRAY_SIZE(nfs4_callback_version),	/* Number of entries */
	.pg_vers = nfs4_callback_version,		/* version table */
	.pg_name = "NFSv4 callback",			/* service name */
	.pg_class = "nfs",				/* authentication class */
	.pg_stats = &nfs4_callback_stats,
	.pg_authenticate = nfs_callback_authenticate,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfs/callback.c
	3	*
	4	* Copyright (C) 2004 Trond Myklebust
	5	*
	6	* NFSv4 callback handling
	7	*/
	8
1da177e4 LT	9	#include <linux/completion.h>
	10	#include <linux/ip.h>
	11	#include <linux/module.h>
	12	#include <linux/smp_lock.h>
	13	#include <linux/sunrpc/svc.h>
	14	#include <linux/sunrpc/svcsock.h>
	15	#include <linux/nfs_fs.h>
353ab6e9	16	#include <linux/mutex.h>
83144186	17	#include <linux/freezer.h>
14c85021 ACM	18
	19	#include <net/inet_sock.h>
	20
4ce79717	21	#include "nfs4_fs.h"
1da177e4	22	#include "callback.h"
24c8dbbb	23	#include "internal.h"
1da177e4 LT	24
	25	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	26
	27	struct nfs_callback_data {
	28	unsigned int users;
	29	struct svc_serv *serv;
	30	pid_t pid;
	31	struct completion started;
	32	struct completion stopped;
	33	};
	34
	35	static struct nfs_callback_data nfs_callback_info;
353ab6e9	36	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	37	static struct svc_program nfs4_callback_program;
1da177e4 LT	38
a72b4422	39	unsigned int nfs_callback_set_tcpport;
1da177e4	40	unsigned short nfs_callback_tcpport;
7d4e2747 DH	41	static const int nfs_set_port_min = 0;
	42	static const int nfs_set_port_max = 65535;
	43
	44	static int param_set_port(const char val, struct kernel_param kp)
	45	{
	46	char *endp;
	47	int num = simple_strtol(val, &endp, 0);
	48	if (endp == val \|\| *endp \|\| num < nfs_set_port_min \|\| num > nfs_set_port_max)
	49	return -EINVAL;
	50	((int )kp->arg) = num;
	51	return 0;
	52	}
	53
	54	module_param_call(callback_tcpport, param_set_port, param_get_int,
	55	&nfs_callback_set_tcpport, 0644);
1da177e4 LT	56
	57	/*
	58	* This is the callback kernel thread.
	59	*/
	60	static void nfs_callback_svc(struct svc_rqst *rqstp)
	61	{
1da177e4 LT	62	int err;
	63
	64	__module_get(THIS_MODULE);
	65	lock_kernel();
	66
	67	nfs_callback_info.pid = current->pid;
	68	daemonize("nfsv4-svc");
	69	/* Process request with signals blocked, but allow SIGKILL. */
	70	allow_signal(SIGKILL);
83144186	71	set_freezable();
1da177e4 LT	72
	73	complete(&nfs_callback_info.started);
	74
1dd761e9 TM	75	for(;;) {
	76	if (signalled()) {
	77	if (nfs_callback_info.users == 0)
	78	break;
	79	flush_signals(current);
	80	}
1da177e4 LT	81	/*
	82	* Listen for a request on the socket
	83	*/
6fb2b47f	84	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
1da177e4 LT	85	if (err == -EAGAIN \|\| err == -EINTR)
	86	continue;
	87	if (err < 0) {
	88	printk(KERN_WARNING
	89	"%s: terminating on error %d\n",
	90	__FUNCTION__, -err);
	91	break;
	92	}
6fb2b47f	93	svc_process(rqstp);
1da177e4 LT	94	}
1da177e4 LT	95
f25bc349	96	svc_exit_thread(rqstp);
1da177e4 LT	97	nfs_callback_info.pid = 0;
	98	complete(&nfs_callback_info.stopped);
	99	unlock_kernel();
	100	module_put_and_exit(0);
	101	}
	102
	103	/*
	104	* Bring up the server process if it is not already up.
	105	*/
	106	int nfs_callback_up(void)
	107	{
	108	struct svc_serv *serv;
1da177e4 LT	109	int ret = 0;
	110
	111	lock_kernel();
353ab6e9	112	mutex_lock(&nfs_callback_mutex);
1da177e4 LT	113	if (nfs_callback_info.users++ \|\| nfs_callback_info.pid != 0)
	114	goto out;
	115	init_completion(&nfs_callback_info.started);
	116	init_completion(&nfs_callback_info.stopped);
bc591ccf	117	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
1da177e4 LT	118	ret = -ENOMEM;
	119	if (!serv)
	120	goto out_err;
482fb94e	121
d7c9f1ed TT	122	ret = svc_create_xprt(serv, "tcp", nfs_callback_set_tcpport,
d7c9f1ed TT	123	SVC_SOCK_ANONYMOUS);
482fb94e	124	if (ret <= 0)
1da177e4	125	goto out_destroy;
482fb94e CL	126	nfs_callback_tcpport = ret;
	127	dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);
	128
1da177e4 LT	129	ret = svc_create_thread(nfs_callback_svc, serv);
	130	if (ret < 0)
	131	goto out_destroy;
	132	nfs_callback_info.serv = serv;
	133	wait_for_completion(&nfs_callback_info.started);
	134	out:
353ab6e9	135	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	136	unlock_kernel();
	137	return ret;
	138	out_destroy:
482fb94e CL	139	dprintk("Couldn't create callback socket or server thread; err = %d\n",
482fb94e CL	140	ret);
1da177e4 LT	141	svc_destroy(serv);
	142	out_err:
	143	nfs_callback_info.users--;
	144	goto out;
	145	}
	146
	147	/*
	148	* Kill the server process if it is not already up.
	149	*/
5ae1fbce	150	void nfs_callback_down(void)
1da177e4	151	{
1da177e4	152	lock_kernel();
353ab6e9	153	mutex_lock(&nfs_callback_mutex);
1dd761e9 TM	154	nfs_callback_info.users--;
	155	do {
	156	if (nfs_callback_info.users != 0 \|\| nfs_callback_info.pid == 0)
	157	break;
	158	if (kill_proc(nfs_callback_info.pid, SIGKILL, 1) < 0)
	159	break;
	160	} while (wait_for_completion_timeout(&nfs_callback_info.stopped, 5*HZ) == 0);
353ab6e9	161	mutex_unlock(&nfs_callback_mutex);
1da177e4	162	unlock_kernel();
1da177e4 LT	163	}
	164
	165	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
	166	{
adfa6f98	167	struct nfs_client *clp;
ad06e4bd	168	char buf[RPC_MAX_ADDRBUFLEN];
1da177e4 LT	169
1da177e4 LT	170	/* Don't talk to strangers */
ff052645	171	clp = nfs_find_client(svc_addr(rqstp), 4);
1da177e4 LT	172	if (clp == NULL)
1da177e4 LT	173	return SVC_DROP;
ad06e4bd CL	174
	175	dprintk("%s: %s NFSv4 callback!\n", __FUNCTION__,
	176	svc_print_addr(rqstp, buf, sizeof(buf)));
24c8dbbb	177	nfs_put_client(clp);
ad06e4bd	178
1da177e4 LT	179	switch (rqstp->rq_authop->flavour) {
	180	case RPC_AUTH_NULL:
	181	if (rqstp->rq_proc != CB_NULL)
	182	return SVC_DENIED;
	183	break;
	184	case RPC_AUTH_UNIX:
	185	break;
	186	case RPC_AUTH_GSS:
	187	/* FIXME: RPCSEC_GSS handling? */
	188	default:
	189	return SVC_DENIED;
	190	}
	191	return SVC_OK;
	192	}
	193
	194	/*
	195	* Define NFS4 callback program
	196	*/
1da177e4 LT	197	static struct svc_version *nfs4_callback_version[] = {
	198	[1] = &nfs4_callback_version1,
	199	};
	200
	201	static struct svc_stat nfs4_callback_stats;
	202
	203	static struct svc_program nfs4_callback_program = {
	204	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	205	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	206	.pg_vers = nfs4_callback_version, /* version table */
	207	.pg_name = "NFSv4 callback", /* service name */
	208	.pg_class = "nfs", /* authentication class */
	209	.pg_stats = &nfs4_callback_stats,
	210	.pg_authenticate = nfs_callback_authenticate,
	211	};