[linux-2.6-block.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

#define XDR_ADDRBUF_LEN		(20)

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;
	struct rpc_message msg = {
		.rpc_argp	= &args,
		.rpc_resp	= res,
	};

	clnt = nsm_create();
	if (IS_ERR(clnt)) {
		status = PTR_ERR(clnt);
		goto out;
	}

	memset(&args, 0, sizeof(args));
	args.mon_name = nsm->sm_name;
	args.addr = nsm_addr_in(nsm)->sin_addr.s_addr;
	args.prog = NLM_PROGRAM;
	args.vers = 3;
	args.proc = NLMPROC_NSM_NOTIFY;
	memset(res, 0, sizeof(*res));

	msg.rpc_proc = &clnt->cl_procinfo[proc];
	status = rpc_call_sync(clnt, &msg, 0);
	if (status < 0)
		printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n",
			status);
	else
		status = 0;
	rpc_shutdown_client(clnt);
 out:
	return status;
}

/*
 * Set up monitoring of a remote host
 */
int
nsm_monitor(struct nlm_host *host)
{
	struct nsm_handle *nsm = host->h_nsmhandle;
	struct nsm_res	res;
	int		status;

	dprintk("lockd: nsm_monitor(%s)\n", host->h_name);
	BUG_ON(nsm == NULL);

	if (nsm->sm_monitored)
		return 0;

	status = nsm_mon_unmon(nsm, SM_MON, &res);

	if (status < 0 || res.status != 0)
		printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_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 (nsm == NULL)
		return 0;
	host->h_nsmhandle = NULL;

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

		status = nsm_mon_unmon(nsm, SM_UNMON, &res);
		if (status < 0)
			printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
					host->h_name);
		else
			nsm->sm_monitored = 0;
	}
	nsm_release(nsm);
	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.
 *
 * Linux uses a text version of the IP address of the remote
 * host as the host identifier (the "mon_name" argument).
 *
 * Linux statd always looks up the canonical hostname first for
 * whatever remote hostname it receives, so this works alright.
 */
static __be32 *xdr_encode_mon_name(__be32 *p, struct nsm_args *argp)
{
	char	buffer[XDR_ADDRBUF_LEN + 1];
	char	*name = argp->mon_name;

	if (!nsm_use_hostnames) {
		snprintf(buffer, XDR_ADDRBUF_LEN,
			 "%pI4", &argp->addr);
		name = buffer;
	}

	return xdr_encode_nsm_string(p, 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
49695174 CL	21	#define XDR_ADDRBUF_LEN (20)
49695174 CL	22
1da177e4 LT	23	static struct rpc_clnt * nsm_create(void);
	24
	25	static struct rpc_program nsm_program;
	26
	27	/*
	28	* Local NSM state
	29	*/
460f5cac	30	int nsm_local_state;
1da177e4 LT	31
	32	/*
	33	* Common procedure for SM_MON/SM_UNMON calls
	34	*/
	35	static int
9502c522	36	nsm_mon_unmon(struct nsm_handle nsm, u32 proc, struct nsm_res res)
1da177e4 LT	37	{
	38	struct rpc_clnt *clnt;
	39	int status;
	40	struct nsm_args args;
dead28da CL	41	struct rpc_message msg = {
	42	.rpc_argp = &args,
	43	.rpc_resp = res,
	44	};
1da177e4 LT	45
	46	clnt = nsm_create();
	47	if (IS_ERR(clnt)) {
	48	status = PTR_ERR(clnt);
	49	goto out;
	50	}
	51
9502c522	52	memset(&args, 0, sizeof(args));
abd1f500	53	args.mon_name = nsm->sm_name;
7e9d7746	54	args.addr = nsm_addr_in(nsm)->sin_addr.s_addr;
1da177e4	55	args.prog = NLM_PROGRAM;
9502c522	56	args.vers = 3;
1da177e4 LT	57	args.proc = NLMPROC_NSM_NOTIFY;
	58	memset(res, 0, sizeof(*res));
	59
dead28da CL	60	msg.rpc_proc = &clnt->cl_procinfo[proc];
dead28da CL	61	status = rpc_call_sync(clnt, &msg, 0);
1da177e4 LT	62	if (status < 0)
	63	printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n",
	64	status);
	65	else
	66	status = 0;
90c5755f	67	rpc_shutdown_client(clnt);
1da177e4 LT	68	out:
	69	return status;
	70	}
	71
	72	/*
	73	* Set up monitoring of a remote host
	74	*/
	75	int
	76	nsm_monitor(struct nlm_host *host)
	77	{
8dead0db	78	struct nsm_handle *nsm = host->h_nsmhandle;
1da177e4 LT	79	struct nsm_res res;
	80	int status;
	81
	82	dprintk("lockd: nsm_monitor(%s)\n", host->h_name);
8dead0db OK	83	BUG_ON(nsm == NULL);
	84
	85	if (nsm->sm_monitored)
977faf39	86	return 0;
1da177e4	87
9502c522	88	status = nsm_mon_unmon(nsm, SM_MON, &res);
1da177e4 LT	89
	90	if (status < 0 \|\| res.status != 0)
	91	printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name);
	92	else
8dead0db	93	nsm->sm_monitored = 1;
1da177e4 LT	94	return status;
	95	}
	96
	97	/*
	98	* Cease to monitor remote host
	99	*/
	100	int
	101	nsm_unmonitor(struct nlm_host *host)
	102	{
8dead0db	103	struct nsm_handle *nsm = host->h_nsmhandle;
1da177e4	104	struct nsm_res res;
977faf39	105	int status = 0;
1da177e4	106
8dead0db	107	if (nsm == NULL)
977faf39	108	return 0;
8dead0db	109	host->h_nsmhandle = NULL;
977faf39	110
9502c522 OK	111	if (atomic_read(&nsm->sm_count) == 1
	112	&& nsm->sm_monitored && !nsm->sm_sticky) {
	113	dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name);
	114
	115	status = nsm_mon_unmon(nsm, SM_UNMON, &res);
977faf39	116	if (status < 0)
9502c522 OK	117	printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
	118	host->h_name);
	119	else
	120	nsm->sm_monitored = 0;
977faf39	121	}
8dead0db	122	nsm_release(nsm);
1da177e4 LT	123	return status;
	124	}
	125
	126	/*
	127	* Create NSM client for the local host
	128	*/
	129	static struct rpc_clnt *
	130	nsm_create(void)
	131	{
e1ec7892 CL	132	struct sockaddr_in sin = {
	133	.sin_family = AF_INET,
	134	.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
	135	.sin_port = 0,
	136	};
	137	struct rpc_create_args args = {
0896a725	138	.protocol = XPRT_TRANSPORT_UDP,
e1ec7892 CL	139	.address = (struct sockaddr *)&sin,
	140	.addrsize = sizeof(sin),
	141	.servername = "localhost",
	142	.program = &nsm_program,
	143	.version = SM_VERSION,
	144	.authflavor = RPC_AUTH_NULL,
e1ec7892 CL	145	};
	146
	147	return rpc_create(&args);
1da177e4 LT	148	}
	149
	150	/*
	151	* XDR functions for NSM.
2ca7754d CL	152	*
	153	* See http://www.opengroup.org/ for details on the Network
	154	* Status Monitor wire protocol.
1da177e4 LT	155	*/
1da177e4 LT	156
099bd05f CL	157	static __be32 xdr_encode_nsm_string(__be32 p, char *string)
	158	{
	159	size_t len = strlen(string);
	160
	161	if (len > SM_MAXSTRLEN)
	162	len = SM_MAXSTRLEN;
	163	return xdr_encode_opaque(p, string, len);
	164	}
	165
49695174 CL	166	/*
	167	* "mon_name" specifies the host to be monitored.
	168	*
	169	* Linux uses a text version of the IP address of the remote
	170	* host as the host identifier (the "mon_name" argument).
	171	*
	172	* Linux statd always looks up the canonical hostname first for
	173	* whatever remote hostname it receives, so this works alright.
	174	*/
	175	static __be32 xdr_encode_mon_name(__be32 p, struct nsm_args *argp)
	176	{
	177	char buffer[XDR_ADDRBUF_LEN + 1];
	178	char *name = argp->mon_name;
	179
	180	if (!nsm_use_hostnames) {
	181	snprintf(buffer, XDR_ADDRBUF_LEN,
be859405	182	"%pI4", &argp->addr);
49695174 CL	183	name = buffer;
	184	}
	185
	186	return xdr_encode_nsm_string(p, name);
	187	}
	188
850c95fd CL	189	/*
	190	* The "my_id" argument specifies the hostname and RPC procedure
	191	* to be called when the status manager receives notification
	192	* (via the SM_NOTIFY call) that the state of host "mon_name"
	193	* has changed.
	194	*/
	195	static __be32 xdr_encode_my_id(__be32 p, struct nsm_args *argp)
	196	{
	197	p = xdr_encode_nsm_string(p, utsname()->nodename);
	198	if (!p)
	199	return ERR_PTR(-EIO);
	200
	201	*p++ = htonl(argp->prog);
	202	*p++ = htonl(argp->vers);
	203	*p++ = htonl(argp->proc);
	204
	205	return p;
	206	}
	207
ea72a7f1 CL	208	/*
	209	* The "mon_id" argument specifies the non-private arguments
	210	* of an SM_MON or SM_UNMON call.
	211	*/
	212	static __be32 xdr_encode_mon_id(__be32 p, struct nsm_args *argp)
	213	{
	214	p = xdr_encode_mon_name(p, argp);
	215	if (!p)
	216	return ERR_PTR(-EIO);
	217
	218	return xdr_encode_my_id(p, argp);
	219	}
	220
0490a54a CL	221	/*
	222	* The "priv" argument may contain private information required
	223	* by the SM_MON call. This information will be supplied in the
	224	* SM_NOTIFY call.
	225	*
	226	* Linux provides the raw IP address of the monitored host,
	227	* left in network byte order.
	228	*/
	229	static __be32 xdr_encode_priv(__be32 p, struct nsm_args *argp)
	230	{
	231	*p++ = argp->addr;
	232	*p++ = 0;
	233	*p++ = 0;
	234	*p++ = 0;
	235
	236	return p;
	237	}
	238
1da177e4	239	static int
52921e02	240	xdr_encode_mon(struct rpc_rqst rqstp, __be32 p, struct nsm_args *argp)
1da177e4	241	{
2ca7754d	242	p = xdr_encode_mon_id(p, argp);
1da177e4 LT	243	if (IS_ERR(p))
1da177e4 LT	244	return PTR_ERR(p);
9502c522	245
0490a54a CL	246	p = xdr_encode_priv(p, argp);
	247	if (IS_ERR(p))
	248	return PTR_ERR(p);
	249
1da177e4 LT	250	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
	251	return 0;
	252	}
	253
	254	static int
52921e02	255	xdr_encode_unmon(struct rpc_rqst rqstp, __be32 p, struct nsm_args *argp)
1da177e4	256	{
2ca7754d	257	p = xdr_encode_mon_id(p, argp);
1da177e4 LT	258	if (IS_ERR(p))
	259	return PTR_ERR(p);
	260	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
	261	return 0;
	262	}
	263
	264	static int
52921e02	265	xdr_decode_stat_res(struct rpc_rqst rqstp, __be32 p, struct nsm_res *resp)
1da177e4 LT	266	{
	267	resp->status = ntohl(*p++);
	268	resp->state = ntohl(*p++);
	269	dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
	270	resp->status, resp->state);
	271	return 0;
	272	}
	273
	274	static int
52921e02	275	xdr_decode_stat(struct rpc_rqst rqstp, __be32 p, struct nsm_res *resp)
1da177e4 LT	276	{
	277	resp->state = ntohl(*p++);
	278	return 0;
	279	}
	280
	281	#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
2ca7754d CL	282	#define SM_my_id_sz (SM_my_name_sz+3)
	283	#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
	284	#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
0490a54a CL	285	#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
0490a54a CL	286	#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
1da177e4 LT	287	#define SM_monres_sz 2
	288	#define SM_unmonres_sz 1
	289
1da177e4 LT	290	static struct rpc_procinfo nsm_procedures[] = {
	291	[SM_MON] = {
	292	.p_proc = SM_MON,
	293	.p_encode = (kxdrproc_t) xdr_encode_mon,
	294	.p_decode = (kxdrproc_t) xdr_decode_stat_res,
2bea90d4 CL	295	.p_arglen = SM_mon_sz,
2bea90d4 CL	296	.p_replen = SM_monres_sz,
cc0175c1 CL	297	.p_statidx = SM_MON,
cc0175c1 CL	298	.p_name = "MONITOR",
1da177e4 LT	299	},
	300	[SM_UNMON] = {
	301	.p_proc = SM_UNMON,
	302	.p_encode = (kxdrproc_t) xdr_encode_unmon,
	303	.p_decode = (kxdrproc_t) xdr_decode_stat,
2bea90d4 CL	304	.p_arglen = SM_mon_id_sz,
2bea90d4 CL	305	.p_replen = SM_unmonres_sz,
cc0175c1 CL	306	.p_statidx = SM_UNMON,
cc0175c1 CL	307	.p_name = "UNMONITOR",
1da177e4 LT	308	},
	309	};
	310
	311	static struct rpc_version nsm_version1 = {
e8c96f8c TK	312	.number = 1,
e8c96f8c TK	313	.nrprocs = ARRAY_SIZE(nsm_procedures),
1da177e4 LT	314	.procs = nsm_procedures
	315	};
	316
	317	static struct rpc_version * nsm_version[] = {
	318	[1] = &nsm_version1,
	319	};
	320
	321	static struct rpc_stat nsm_stats;
	322
	323	static struct rpc_program nsm_program = {
	324	.name = "statd",
	325	.number = SM_PROGRAM,
e8c96f8c	326	.nrvers = ARRAY_SIZE(nsm_version),
1da177e4 LT	327	.version = nsm_version,
	328	.stats = &nsm_stats
	329	};