[mirror_ubuntu-bionic-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/smp_lock.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/nfs_fs.h>
#include <linux/mutex.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)
{
	struct svc_serv *serv = rqstp->rq_server;
	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);

	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(serv, 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;
		}
		dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__,
				NIPQUAD(rqstp->rq_addr.sin_addr.s_addr));
		svc_process(serv, 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;
	struct svc_sock *svsk;
	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);
	ret = -ENOMEM;
	if (!serv)
		goto out_err;
	/* FIXME: We don't want to register this socket with the portmapper */
	ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport);
	if (ret < 0)
		goto out_destroy;
	if (!list_empty(&serv->sv_permsocks)) {
		svsk = list_entry(serv->sv_permsocks.next,
				struct svc_sock, sk_list);
		nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport);
		dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport);
	} else
		BUG();
	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:
	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 sockaddr_in *addr = &rqstp->rq_addr;
	struct nfs_client *clp;

	/* Don't talk to strangers */
	clp = nfs_find_client(addr, 4);
	if (clp == NULL)
		return SVC_DROP;
	dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr->sin_addr));
	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>
14c85021 ACM	17
	18	#include <net/inet_sock.h>
	19
4ce79717	20	#include "nfs4_fs.h"
1da177e4	21	#include "callback.h"
24c8dbbb	22	#include "internal.h"
1da177e4 LT	23
	24	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	25
	26	struct nfs_callback_data {
	27	unsigned int users;
	28	struct svc_serv *serv;
	29	pid_t pid;
	30	struct completion started;
	31	struct completion stopped;
	32	};
	33
	34	static struct nfs_callback_data nfs_callback_info;
353ab6e9	35	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	36	static struct svc_program nfs4_callback_program;
1da177e4 LT	37
a72b4422	38	unsigned int nfs_callback_set_tcpport;
1da177e4	39	unsigned short nfs_callback_tcpport;
7d4e2747 DH	40	static const int nfs_set_port_min = 0;
	41	static const int nfs_set_port_max = 65535;
	42
	43	static int param_set_port(const char val, struct kernel_param kp)
	44	{
	45	char *endp;
	46	int num = simple_strtol(val, &endp, 0);
	47	if (endp == val \|\| *endp \|\| num < nfs_set_port_min \|\| num > nfs_set_port_max)
	48	return -EINVAL;
	49	((int )kp->arg) = num;
	50	return 0;
	51	}
	52
	53	module_param_call(callback_tcpport, param_set_port, param_get_int,
	54	&nfs_callback_set_tcpport, 0644);
1da177e4 LT	55
	56	/*
	57	* This is the callback kernel thread.
	58	*/
	59	static void nfs_callback_svc(struct svc_rqst *rqstp)
	60	{
	61	struct svc_serv *serv = rqstp->rq_server;
	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);
	71
	72	complete(&nfs_callback_info.started);
	73
1dd761e9 TM	74	for(;;) {
	75	if (signalled()) {
	76	if (nfs_callback_info.users == 0)
	77	break;
	78	flush_signals(current);
	79	}
1da177e4 LT	80	/*
	81	* Listen for a request on the socket
	82	*/
	83	err = svc_recv(serv, rqstp, MAX_SCHEDULE_TIMEOUT);
	84	if (err == -EAGAIN \|\| err == -EINTR)
	85	continue;
	86	if (err < 0) {
	87	printk(KERN_WARNING
	88	"%s: terminating on error %d\n",
	89	__FUNCTION__, -err);
	90	break;
	91	}
	92	dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__,
	93	NIPQUAD(rqstp->rq_addr.sin_addr.s_addr));
	94	svc_process(serv, rqstp);
	95	}
	96
f25bc349	97	svc_exit_thread(rqstp);
1da177e4 LT	98	nfs_callback_info.pid = 0;
	99	complete(&nfs_callback_info.stopped);
	100	unlock_kernel();
	101	module_put_and_exit(0);
	102	}
	103
	104	/*
	105	* Bring up the server process if it is not already up.
	106	*/
	107	int nfs_callback_up(void)
	108	{
	109	struct svc_serv *serv;
	110	struct svc_sock *svsk;
	111	int ret = 0;
	112
	113	lock_kernel();
353ab6e9	114	mutex_lock(&nfs_callback_mutex);
1da177e4 LT	115	if (nfs_callback_info.users++ \|\| nfs_callback_info.pid != 0)
	116	goto out;
	117	init_completion(&nfs_callback_info.started);
	118	init_completion(&nfs_callback_info.stopped);
	119	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE);
	120	ret = -ENOMEM;
	121	if (!serv)
	122	goto out_err;
	123	/* FIXME: We don't want to register this socket with the portmapper */
a72b4422	124	ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport);
1da177e4 LT	125	if (ret < 0)
	126	goto out_destroy;
	127	if (!list_empty(&serv->sv_permsocks)) {
	128	svsk = list_entry(serv->sv_permsocks.next,
	129	struct svc_sock, sk_list);
	130	nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport);
	131	dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport);
	132	} else
	133	BUG();
	134	ret = svc_create_thread(nfs_callback_svc, serv);
	135	if (ret < 0)
	136	goto out_destroy;
	137	nfs_callback_info.serv = serv;
	138	wait_for_completion(&nfs_callback_info.started);
	139	out:
353ab6e9	140	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	141	unlock_kernel();
	142	return ret;
	143	out_destroy:
	144	svc_destroy(serv);
	145	out_err:
	146	nfs_callback_info.users--;
	147	goto out;
	148	}
	149
	150	/*
	151	* Kill the server process if it is not already up.
	152	*/
5ae1fbce	153	void nfs_callback_down(void)
1da177e4	154	{
1da177e4	155	lock_kernel();
353ab6e9	156	mutex_lock(&nfs_callback_mutex);
1dd761e9 TM	157	nfs_callback_info.users--;
	158	do {
	159	if (nfs_callback_info.users != 0 \|\| nfs_callback_info.pid == 0)
	160	break;
	161	if (kill_proc(nfs_callback_info.pid, SIGKILL, 1) < 0)
	162	break;
	163	} while (wait_for_completion_timeout(&nfs_callback_info.stopped, 5*HZ) == 0);
353ab6e9	164	mutex_unlock(&nfs_callback_mutex);
1da177e4	165	unlock_kernel();
1da177e4 LT	166	}
	167
	168	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
	169	{
24c8dbbb	170	struct sockaddr_in *addr = &rqstp->rq_addr;
adfa6f98	171	struct nfs_client *clp;
1da177e4 LT	172
1da177e4 LT	173	/* Don't talk to strangers */
24c8dbbb	174	clp = nfs_find_client(addr, 4);
1da177e4 LT	175	if (clp == NULL)
1da177e4 LT	176	return SVC_DROP;
24c8dbbb DH	177	dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr->sin_addr));
24c8dbbb DH	178	nfs_put_client(clp);
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	};