[deliverable/linux.git] / fs / lockd / mon.c

/*
 * linux/fs/lockd/mon.c
 *
 * The kernel statd client.
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/utsname.h>
#include <linux/kernel.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/xprtsock.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/sm_inter.h>


#define NLMDBG_FACILITY		NLMDBG_MONITOR

static struct rpc_clnt *	nsm_create(void);

static struct rpc_program	nsm_program;

/*
 * Local NSM state
 */
int				nsm_local_state;

/*
 * Common procedure for SM_MON/SM_UNMON calls
 */
static int
nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
{
	struct rpc_clnt	*clnt;
	int		status;
	struct nsm_args args = {
		.addr		= nsm_addr_in(nsm)->sin_addr.s_addr,
		.prog		= NLM_PROGRAM,
		.vers		= 3,
		.proc		= NLMPROC_NSM_NOTIFY,
		.mon_name	= nsm->sm_mon_name,
	};
	struct rpc_message msg = {
		.rpc_argp	= &args,
		.rpc_resp	= res,
	};

	clnt = nsm_create();
	if (IS_ERR(clnt)) {
		status = PTR_ERR(clnt);
		dprintk("lockd: failed to create NSM upcall transport, "
				"status=%d\n", status);
		goto out;
	}

	memset(res, 0, sizeof(*res));

	msg.rpc_proc = &clnt->cl_procinfo[proc];
	status = rpc_call_sync(clnt, &msg, 0);
	if (status < 0)
		dprintk("lockd: NSM upcall RPC failed, status=%d\n",
				status);
	else
		status = 0;
	rpc_shutdown_client(clnt);
 out:
	return status;
}

/**
 * nsm_monitor - Notify a peer in case we reboot
 * @host: pointer to nlm_host of peer to notify
 *
 * If this peer is not already monitored, this function sends an
 * upcall to the local rpc.statd to record the name/address of
 * the peer to notify in case we reboot.
 *
 * Returns zero if the peer is monitored by the local rpc.statd;
 * otherwise a negative errno value is returned.
 */
int nsm_monitor(const struct nlm_host *host)
{
	struct nsm_handle *nsm = host->h_nsmhandle;
	struct nsm_res	res;
	int		status;

	dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);

	if (nsm->sm_monitored)
		return 0;

	/*
	 * Choose whether to record the caller_name or IP address of
	 * this peer in the local rpc.statd's database.
	 */
	nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;

	status = nsm_mon_unmon(nsm, SM_MON, &res);
	if (res.status != 0)
		status = -EIO;
	if (status < 0)
		printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
	else
		nsm->sm_monitored = 1;
	return status;
}

/*
 * Cease to monitor remote host
 */
int
nsm_unmonitor(struct nlm_host *host)
{
	struct nsm_handle *nsm = host->h_nsmhandle;
	struct nsm_res	res;
	int		status = 0;

	if (atomic_read(&nsm->sm_count) == 1
	 && nsm->sm_monitored && !nsm->sm_sticky) {
		dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);

		status = nsm_mon_unmon(nsm, SM_UNMON, &res);
		if (status < 0)
			printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
					nsm->sm_name);
		else
			nsm->sm_monitored = 0;
	}
	return status;
}

/*
 * Create NSM client for the local host
 */
static struct rpc_clnt *
nsm_create(void)
{
	struct sockaddr_in	sin = {
		.sin_family	= AF_INET,
		.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
		.sin_port	= 0,
	};
	struct rpc_create_args args = {
		.protocol	= XPRT_TRANSPORT_UDP,
		.address	= (struct sockaddr *)&sin,
		.addrsize	= sizeof(sin),
		.servername	= "localhost",
		.program	= &nsm_program,
		.version	= SM_VERSION,
		.authflavor	= RPC_AUTH_NULL,
	};

	return rpc_create(&args);
}

/*
 * XDR functions for NSM.
 *
 * See http://www.opengroup.org/ for details on the Network
 * Status Monitor wire protocol.
 */

static __be32 *xdr_encode_nsm_string(__be32 *p, char *string)
{
	size_t len = strlen(string);

	if (len > SM_MAXSTRLEN)
		len = SM_MAXSTRLEN;
	return xdr_encode_opaque(p, string, len);
}

/*
 * "mon_name" specifies the host to be monitored.
 */
static __be32 *xdr_encode_mon_name(__be32 *p, struct nsm_args *argp)
{
	return xdr_encode_nsm_string(p, argp->mon_name);
}

/*
 * The "my_id" argument specifies the hostname and RPC procedure
 * to be called when the status manager receives notification
 * (via the SM_NOTIFY call) that the state of host "mon_name"
 * has changed.
 */
static __be32 *xdr_encode_my_id(__be32 *p, struct nsm_args *argp)
{
	p = xdr_encode_nsm_string(p, utsname()->nodename);
	if (!p)
		return ERR_PTR(-EIO);

	*p++ = htonl(argp->prog);
	*p++ = htonl(argp->vers);
	*p++ = htonl(argp->proc);

	return p;
}

/*
 * The "mon_id" argument specifies the non-private arguments
 * of an SM_MON or SM_UNMON call.
 */
static __be32 *xdr_encode_mon_id(__be32 *p, struct nsm_args *argp)
{
	p = xdr_encode_mon_name(p, argp);
	if (!p)
		return ERR_PTR(-EIO);

	return xdr_encode_my_id(p, argp);
}

/*
 * The "priv" argument may contain private information required
 * by the SM_MON call. This information will be supplied in the
 * SM_NOTIFY call.
 *
 * Linux provides the raw IP address of the monitored host,
 * left in network byte order.
 */
static __be32 *xdr_encode_priv(__be32 *p, struct nsm_args *argp)
{
	*p++ = argp->addr;
	*p++ = 0;
	*p++ = 0;
	*p++ = 0;

	return p;
}

static int
xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
{
	p = xdr_encode_mon_id(p, argp);
	if (IS_ERR(p))
		return PTR_ERR(p);

	p = xdr_encode_priv(p, argp);
	if (IS_ERR(p))
		return PTR_ERR(p);

	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
	return 0;
}

static int
xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
{
	p = xdr_encode_mon_id(p, argp);
	if (IS_ERR(p))
		return PTR_ERR(p);
	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
	return 0;
}

static int
xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp)
{
	resp->status = ntohl(*p++);
	resp->state = ntohl(*p++);
	dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
			resp->status, resp->state);
	return 0;
}

static int
xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp)
{
	resp->state = ntohl(*p++);
	return 0;
}

#define SM_my_name_sz	(1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_my_id_sz	(SM_my_name_sz+3)
#define SM_mon_name_sz	(1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_mon_id_sz	(SM_mon_name_sz+SM_my_id_sz)
#define SM_priv_sz	(XDR_QUADLEN(SM_PRIV_SIZE))
#define SM_mon_sz	(SM_mon_id_sz+SM_priv_sz)
#define SM_monres_sz	2
#define SM_unmonres_sz	1

static struct rpc_procinfo	nsm_procedures[] = {
[SM_MON] = {
		.p_proc		= SM_MON,
		.p_encode	= (kxdrproc_t) xdr_encode_mon,
		.p_decode	= (kxdrproc_t) xdr_decode_stat_res,
		.p_arglen	= SM_mon_sz,
		.p_replen	= SM_monres_sz,
		.p_statidx	= SM_MON,
		.p_name		= "MONITOR",
	},
[SM_UNMON] = {
		.p_proc		= SM_UNMON,
		.p_encode	= (kxdrproc_t) xdr_encode_unmon,
		.p_decode	= (kxdrproc_t) xdr_decode_stat,
		.p_arglen	= SM_mon_id_sz,
		.p_replen	= SM_unmonres_sz,
		.p_statidx	= SM_UNMON,
		.p_name		= "UNMONITOR",
	},
};

static struct rpc_version	nsm_version1 = {
		.number		= 1,
		.nrprocs	= ARRAY_SIZE(nsm_procedures),
		.procs		= nsm_procedures
};

static struct rpc_version *	nsm_version[] = {
	[1] = &nsm_version1,
};

static struct rpc_stat		nsm_stats;

static struct rpc_program	nsm_program = {
		.name		= "statd",
		.number		= SM_PROGRAM,
		.nrvers		= ARRAY_SIZE(nsm_version),
		.version	= nsm_version,
		.stats		= &nsm_stats
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/lockd/mon.c
	3	*
	4	* The kernel statd client.
	5	*
	6	* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
	7	*/
	8
	9	#include <linux/types.h>
	10	#include <linux/utsname.h>
	11	#include <linux/kernel.h>
	12	#include <linux/sunrpc/clnt.h>
0896a725	13	#include <linux/sunrpc/xprtsock.h>
1da177e4 LT	14	#include <linux/sunrpc/svc.h>
	15	#include <linux/lockd/lockd.h>
	16	#include <linux/lockd/sm_inter.h>
	17
	18
	19	#define NLMDBG_FACILITY NLMDBG_MONITOR
	20
	21	static struct rpc_clnt * nsm_create(void);
	22
	23	static struct rpc_program nsm_program;
	24
	25	/*
	26	* Local NSM state
	27	*/
460f5cac	28	int nsm_local_state;
1da177e4 LT	29
	30	/*
	31	* Common procedure for SM_MON/SM_UNMON calls
	32	*/
	33	static int
9502c522	34	nsm_mon_unmon(struct nsm_handle nsm, u32 proc, struct nsm_res res)
1da177e4 LT	35	{
	36	struct rpc_clnt *clnt;
	37	int status;
a4846750 CL	38	struct nsm_args args = {
	39	.addr = nsm_addr_in(nsm)->sin_addr.s_addr,
	40	.prog = NLM_PROGRAM,
	41	.vers = 3,
	42	.proc = NLMPROC_NSM_NOTIFY,
29ed1407	43	.mon_name = nsm->sm_mon_name,
a4846750	44	};
dead28da CL	45	struct rpc_message msg = {
	46	.rpc_argp = &args,
	47	.rpc_resp = res,
	48	};
1da177e4 LT	49
	50	clnt = nsm_create();
	51	if (IS_ERR(clnt)) {
	52	status = PTR_ERR(clnt);
5acf4315 CL	53	dprintk("lockd: failed to create NSM upcall transport, "
5acf4315 CL	54	"status=%d\n", status);
1da177e4 LT	55	goto out;
	56	}
	57
1da177e4 LT	58	memset(res, 0, sizeof(*res));
1da177e4 LT	59
dead28da CL	60	msg.rpc_proc = &clnt->cl_procinfo[proc];
dead28da CL	61	status = rpc_call_sync(clnt, &msg, 0);
1da177e4	62	if (status < 0)
5acf4315 CL	63	dprintk("lockd: NSM upcall RPC failed, status=%d\n",
5acf4315 CL	64	status);
1da177e4 LT	65	else
1da177e4 LT	66	status = 0;
90c5755f	67	rpc_shutdown_client(clnt);
1da177e4 LT	68	out:
	69	return status;
	70	}
	71
1e49323c CL	72	/**
	73	* nsm_monitor - Notify a peer in case we reboot
	74	* @host: pointer to nlm_host of peer to notify
	75	*
	76	* If this peer is not already monitored, this function sends an
	77	* upcall to the local rpc.statd to record the name/address of
	78	* the peer to notify in case we reboot.
	79	*
	80	* Returns zero if the peer is monitored by the local rpc.statd;
	81	* otherwise a negative errno value is returned.
1da177e4	82	*/
1e49323c	83	int nsm_monitor(const struct nlm_host *host)
1da177e4	84	{
8dead0db	85	struct nsm_handle *nsm = host->h_nsmhandle;
1da177e4 LT	86	struct nsm_res res;
	87	int status;
	88
9fee4902	89	dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
8dead0db OK	90
8dead0db OK	91	if (nsm->sm_monitored)
977faf39	92	return 0;
1da177e4	93
29ed1407 CL	94	/*
	95	* Choose whether to record the caller_name or IP address of
	96	* this peer in the local rpc.statd's database.
	97	*/
	98	nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
	99
9502c522	100	status = nsm_mon_unmon(nsm, SM_MON, &res);
5d254b11 CL	101	if (res.status != 0)
	102	status = -EIO;
	103	if (status < 0)
9fee4902	104	printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
1da177e4	105	else
8dead0db	106	nsm->sm_monitored = 1;
1da177e4 LT	107	return status;
	108	}
	109
	110	/*
	111	* Cease to monitor remote host
	112	*/
	113	int
	114	nsm_unmonitor(struct nlm_host *host)
	115	{
8dead0db	116	struct nsm_handle *nsm = host->h_nsmhandle;
1da177e4	117	struct nsm_res res;
977faf39	118	int status = 0;
1da177e4	119
9502c522 OK	120	if (atomic_read(&nsm->sm_count) == 1
9502c522 OK	121	&& nsm->sm_monitored && !nsm->sm_sticky) {
9fee4902	122	dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
9502c522 OK	123
9502c522 OK	124	status = nsm_mon_unmon(nsm, SM_UNMON, &res);
977faf39	125	if (status < 0)
9502c522	126	printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
9fee4902	127	nsm->sm_name);
9502c522 OK	128	else
9502c522 OK	129	nsm->sm_monitored = 0;
977faf39	130	}
1da177e4 LT	131	return status;
	132	}
	133
	134	/*
	135	* Create NSM client for the local host
	136	*/
	137	static struct rpc_clnt *
	138	nsm_create(void)
	139	{
e1ec7892 CL	140	struct sockaddr_in sin = {
	141	.sin_family = AF_INET,
	142	.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
	143	.sin_port = 0,
	144	};
	145	struct rpc_create_args args = {
0896a725	146	.protocol = XPRT_TRANSPORT_UDP,
e1ec7892 CL	147	.address = (struct sockaddr *)&sin,
	148	.addrsize = sizeof(sin),
	149	.servername = "localhost",
	150	.program = &nsm_program,
	151	.version = SM_VERSION,
	152	.authflavor = RPC_AUTH_NULL,
e1ec7892 CL	153	};
	154
	155	return rpc_create(&args);
1da177e4 LT	156	}
	157
	158	/*
	159	* XDR functions for NSM.
2ca7754d CL	160	*
	161	* See http://www.opengroup.org/ for details on the Network
	162	* Status Monitor wire protocol.
1da177e4 LT	163	*/
1da177e4 LT	164
099bd05f CL	165	static __be32 xdr_encode_nsm_string(__be32 p, char *string)
	166	{
	167	size_t len = strlen(string);
	168
	169	if (len > SM_MAXSTRLEN)
	170	len = SM_MAXSTRLEN;
	171	return xdr_encode_opaque(p, string, len);
	172	}
	173
49695174 CL	174	/*
49695174 CL	175	* "mon_name" specifies the host to be monitored.
49695174 CL	176	*/
	177	static __be32 xdr_encode_mon_name(__be32 p, struct nsm_args *argp)
	178	{
29ed1407	179	return xdr_encode_nsm_string(p, argp->mon_name);
49695174 CL	180	}
49695174 CL	181
850c95fd CL	182	/*
	183	* The "my_id" argument specifies the hostname and RPC procedure
	184	* to be called when the status manager receives notification
	185	* (via the SM_NOTIFY call) that the state of host "mon_name"
	186	* has changed.
	187	*/
	188	static __be32 xdr_encode_my_id(__be32 p, struct nsm_args *argp)
	189	{
	190	p = xdr_encode_nsm_string(p, utsname()->nodename);
	191	if (!p)
	192	return ERR_PTR(-EIO);
	193
	194	*p++ = htonl(argp->prog);
	195	*p++ = htonl(argp->vers);
	196	*p++ = htonl(argp->proc);
	197
	198	return p;
	199	}
	200
ea72a7f1 CL	201	/*
	202	* The "mon_id" argument specifies the non-private arguments
	203	* of an SM_MON or SM_UNMON call.
	204	*/
	205	static __be32 xdr_encode_mon_id(__be32 p, struct nsm_args *argp)
	206	{
	207	p = xdr_encode_mon_name(p, argp);
	208	if (!p)
	209	return ERR_PTR(-EIO);
	210
	211	return xdr_encode_my_id(p, argp);
	212	}
	213
0490a54a CL	214	/*
	215	* The "priv" argument may contain private information required
	216	* by the SM_MON call. This information will be supplied in the
	217	* SM_NOTIFY call.
	218	*
	219	* Linux provides the raw IP address of the monitored host,
	220	* left in network byte order.
	221	*/
	222	static __be32 xdr_encode_priv(__be32 p, struct nsm_args *argp)
	223	{
	224	*p++ = argp->addr;
	225	*p++ = 0;
	226	*p++ = 0;
	227	*p++ = 0;
	228
	229	return p;
	230	}
	231
1da177e4	232	static int
52921e02	233	xdr_encode_mon(struct rpc_rqst rqstp, __be32 p, struct nsm_args *argp)
1da177e4	234	{
2ca7754d	235	p = xdr_encode_mon_id(p, argp);
1da177e4 LT	236	if (IS_ERR(p))
1da177e4 LT	237	return PTR_ERR(p);
9502c522	238
0490a54a CL	239	p = xdr_encode_priv(p, argp);
	240	if (IS_ERR(p))
	241	return PTR_ERR(p);
	242
1da177e4 LT	243	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
	244	return 0;
	245	}
	246
	247	static int
52921e02	248	xdr_encode_unmon(struct rpc_rqst rqstp, __be32 p, struct nsm_args *argp)
1da177e4	249	{
2ca7754d	250	p = xdr_encode_mon_id(p, argp);
1da177e4 LT	251	if (IS_ERR(p))
	252	return PTR_ERR(p);
	253	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
	254	return 0;
	255	}
	256
	257	static int
52921e02	258	xdr_decode_stat_res(struct rpc_rqst rqstp, __be32 p, struct nsm_res *resp)
1da177e4 LT	259	{
	260	resp->status = ntohl(*p++);
	261	resp->state = ntohl(*p++);
	262	dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
	263	resp->status, resp->state);
	264	return 0;
	265	}
	266
	267	static int
52921e02	268	xdr_decode_stat(struct rpc_rqst rqstp, __be32 p, struct nsm_res *resp)
1da177e4 LT	269	{
	270	resp->state = ntohl(*p++);
	271	return 0;
	272	}
	273
	274	#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
2ca7754d CL	275	#define SM_my_id_sz (SM_my_name_sz+3)
	276	#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
	277	#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
0490a54a CL	278	#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
0490a54a CL	279	#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
1da177e4 LT	280	#define SM_monres_sz 2
	281	#define SM_unmonres_sz 1
	282
1da177e4 LT	283	static struct rpc_procinfo nsm_procedures[] = {
	284	[SM_MON] = {
	285	.p_proc = SM_MON,
	286	.p_encode = (kxdrproc_t) xdr_encode_mon,
	287	.p_decode = (kxdrproc_t) xdr_decode_stat_res,
2bea90d4 CL	288	.p_arglen = SM_mon_sz,
2bea90d4 CL	289	.p_replen = SM_monres_sz,
cc0175c1 CL	290	.p_statidx = SM_MON,
cc0175c1 CL	291	.p_name = "MONITOR",
1da177e4 LT	292	},
	293	[SM_UNMON] = {
	294	.p_proc = SM_UNMON,
	295	.p_encode = (kxdrproc_t) xdr_encode_unmon,
	296	.p_decode = (kxdrproc_t) xdr_decode_stat,
2bea90d4 CL	297	.p_arglen = SM_mon_id_sz,
2bea90d4 CL	298	.p_replen = SM_unmonres_sz,
cc0175c1 CL	299	.p_statidx = SM_UNMON,
cc0175c1 CL	300	.p_name = "UNMONITOR",
1da177e4 LT	301	},
	302	};
	303
	304	static struct rpc_version nsm_version1 = {
e8c96f8c TK	305	.number = 1,
e8c96f8c TK	306	.nrprocs = ARRAY_SIZE(nsm_procedures),
1da177e4 LT	307	.procs = nsm_procedures
	308	};
	309
	310	static struct rpc_version * nsm_version[] = {
	311	[1] = &nsm_version1,
	312	};
	313
	314	static struct rpc_stat nsm_stats;
	315
	316	static struct rpc_program nsm_program = {
	317	.name = "statd",
	318	.number = SM_PROGRAM,
e8c96f8c	319	.nrvers = ARRAY_SIZE(nsm_version),
1da177e4 LT	320	.version = nsm_version,
	321	.stats = &nsm_stats
	322	};