[net-next-2.6.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 NSM_PROGRAM		100024
#define NSM_VERSION		1

enum {
	NSMPROC_NULL,
	NSMPROC_STAT,
	NSMPROC_MON,
	NSMPROC_UNMON,
	NSMPROC_UNMON_ALL,
	NSMPROC_SIMU_CRASH,
	NSMPROC_NOTIFY,
};

struct nsm_args {
	__be32			addr;		/* remote address */
	u32			prog;		/* RPC callback info */
	u32			vers;
	u32			proc;

	char			*mon_name;
};

struct nsm_res {
	u32			status;
	u32			state;
};

static struct rpc_clnt *	nsm_create(void);

static struct rpc_program	nsm_program;
static				LIST_HEAD(nsm_handles);
static				DEFINE_SPINLOCK(nsm_lock);

/*
 * Local NSM state
 */
int				nsm_local_state;

static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf,
				     const size_t len)
{
	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
	snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
}

static void nsm_display_ipv6_address(const struct sockaddr *sap, char *buf,
				     const size_t len)
{
	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;

	if (ipv6_addr_v4mapped(&sin6->sin6_addr))
		snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]);
	else if (sin6->sin6_scope_id != 0)
		snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr,
				sin6->sin6_scope_id);
	else
		snprintf(buf, len, "%pI6", &sin6->sin6_addr);
}

static void nsm_display_address(const struct sockaddr *sap,
				char *buf, const size_t len)
{
	switch (sap->sa_family) {
	case AF_INET:
		nsm_display_ipv4_address(sap, buf, len);
		break;
	case AF_INET6:
		nsm_display_ipv6_address(sap, buf, len);
		break;
	default:
		snprintf(buf, len, "unsupported address family");
		break;
	}
}

/*
 * Common procedure for NSMPROC_MON/NSMPROC_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, NSMPROC_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;
}

/**
 * nsm_unmonitor - Unregister peer notification
 * @host: pointer to nlm_host of peer to stop monitoring
 *
 * If this peer is monitored, this function sends an upcall to
 * tell the local rpc.statd not to send this peer a notification
 * when we reboot.
 */
void nsm_unmonitor(const struct nlm_host *host)
{
	struct nsm_handle *nsm = host->h_nsmhandle;
	struct nsm_res	res;
	int status;

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

/**
 * nsm_find - Find or create a cached nsm_handle
 * @sap: pointer to socket address of handle to find
 * @salen: length of socket address
 * @hostname: pointer to C string containing hostname to find
 * @hostname_len: length of C string
 * @create: one means create new handle if not found in cache
 *
 * Behavior is modulated by the global nsm_use_hostnames variable
 * and by the @create argument.
 *
 * Returns a cached nsm_handle after bumping its ref count, or if
 * @create is set, returns a fresh nsm_handle if a handle that
 * matches @sap and/or @hostname cannot be found in the handle cache.
 * Returns NULL if an error occurs.
 */
struct nsm_handle *nsm_find(const struct sockaddr *sap, const size_t salen,
			    const char *hostname, const size_t hostname_len,
			    const int create)
{
	struct nsm_handle *nsm = NULL;
	struct nsm_handle *pos;

	if (!sap)
		return NULL;

	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
		if (printk_ratelimit()) {
			printk(KERN_WARNING "Invalid hostname \"%.*s\" "
					    "in NFS lock request\n",
				(int)hostname_len, hostname);
		}
		return NULL;
	}

retry:
	spin_lock(&nsm_lock);
	list_for_each_entry(pos, &nsm_handles, sm_link) {

		if (hostname && nsm_use_hostnames) {
			if (strlen(pos->sm_name) != hostname_len
			 || memcmp(pos->sm_name, hostname, hostname_len))
				continue;
		} else if (!nlm_cmp_addr(nsm_addr(pos), sap))
			continue;
		atomic_inc(&pos->sm_count);
		kfree(nsm);
		nsm = pos;
		goto found;
	}
	if (nsm) {
		list_add(&nsm->sm_link, &nsm_handles);
		goto found;
	}
	spin_unlock(&nsm_lock);

	if (!create)
		return NULL;

	nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
	if (nsm == NULL)
		return NULL;

	memcpy(nsm_addr(nsm), sap, salen);
	nsm->sm_addrlen = salen;
	nsm->sm_name = (char *) (nsm + 1);
	memcpy(nsm->sm_name, hostname, hostname_len);
	nsm->sm_name[hostname_len] = '\0';
	nsm_display_address((struct sockaddr *)&nsm->sm_addr,
				nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
	atomic_set(&nsm->sm_count, 1);
	goto retry;

found:
	spin_unlock(&nsm_lock);
	return nsm;
}

/**
 * nsm_release - Release an NSM handle
 * @nsm: pointer to handle to be released
 *
 */
void nsm_release(struct nsm_handle *nsm)
{
	if (!nsm)
		return;
	if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
		list_del(&nsm->sm_link);
		spin_unlock(&nsm_lock);
		kfree(nsm);
	}
}

/*
 * 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	= NSM_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 int encode_nsm_string(struct xdr_stream *xdr, const char *string)
{
	const u32 len = strlen(string);
	__be32 *p;

	if (unlikely(len > SM_MAXSTRLEN))
		return -EIO;
	p = xdr_reserve_space(xdr, sizeof(u32) + len);
	if (unlikely(p == NULL))
		return -EIO;
	xdr_encode_opaque(p, string, len);
	return 0;
}

/*
 * "mon_name" specifies the host to be monitored.
 */
static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
{
	return encode_nsm_string(xdr, argp->mon_name);
}

/*
 * The "my_id" argument specifies the hostname and RPC procedure
 * to be called when the status manager receives notification
 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
 * has changed.
 */
static int encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
{
	int status;
	__be32 *p;

	status = encode_nsm_string(xdr, utsname()->nodename);
	if (unlikely(status != 0))
		return status;
	p = xdr_reserve_space(xdr, 3 * sizeof(u32));
	if (unlikely(p == NULL))
		return -EIO;
	*p++ = htonl(argp->prog);
	*p++ = htonl(argp->vers);
	*p++ = htonl(argp->proc);
	return 0;
}

/*
 * The "mon_id" argument specifies the non-private arguments
 * of an NSMPROC_MON or NSMPROC_UNMON call.
 */
static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
{
	int status;

	status = encode_mon_name(xdr, argp);
	if (unlikely(status != 0))
		return status;
	return encode_my_id(xdr, argp);
}

/*
 * The "priv" argument may contain private information required
 * by the NSMPROC_MON call. This information will be supplied in the
 * NLMPROC_SM_NOTIFY call.
 *
 * Linux provides the raw IP address of the monitored host,
 * left in network byte order.
 */
static int encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
	if (unlikely(p == NULL))
		return -EIO;
	*p++ = argp->addr;
	*p++ = 0;
	*p++ = 0;
	*p++ = 0;
	return 0;
}

static int xdr_enc_mon(struct rpc_rqst *req, __be32 *p,
		       const struct nsm_args *argp)
{
	struct xdr_stream xdr;
	int status;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	status = encode_mon_id(&xdr, argp);
	if (unlikely(status))
		return status;
	return encode_priv(&xdr, argp);
}

static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p,
			 const struct nsm_args *argp)
{
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	return encode_mon_id(&xdr, argp);
}

static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p,
			    struct nsm_res *resp)
{
	struct xdr_stream xdr;

	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	p = xdr_inline_decode(&xdr, 2 * sizeof(u32));
	if (unlikely(p == NULL))
		return -EIO;
	resp->status = ntohl(*p++);
	resp->state = ntohl(*p);

	dprintk("lockd: xdr_dec_stat_res status %d state %d\n",
			resp->status, resp->state);
	return 0;
}

static int xdr_dec_stat(struct rpc_rqst *rqstp, __be32 *p,
			struct nsm_res *resp)
{
	struct xdr_stream xdr;

	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	p = xdr_inline_decode(&xdr, sizeof(u32));
	if (unlikely(p == NULL))
		return -EIO;
	resp->state = ntohl(*p);

	dprintk("lockd: xdr_dec_stat state %d\n", resp->state);
	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[] = {
[NSMPROC_MON] = {
		.p_proc		= NSMPROC_MON,
		.p_encode	= (kxdrproc_t)xdr_enc_mon,
		.p_decode	= (kxdrproc_t)xdr_dec_stat_res,
		.p_arglen	= SM_mon_sz,
		.p_replen	= SM_monres_sz,
		.p_statidx	= NSMPROC_MON,
		.p_name		= "MONITOR",
	},
[NSMPROC_UNMON] = {
		.p_proc		= NSMPROC_UNMON,
		.p_encode	= (kxdrproc_t)xdr_enc_unmon,
		.p_decode	= (kxdrproc_t)xdr_dec_stat,
		.p_arglen	= SM_mon_id_sz,
		.p_replen	= SM_unmonres_sz,
		.p_statidx	= NSMPROC_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		= NSM_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
36e8e668 CL	20	#define NSM_PROGRAM 100024
	21	#define NSM_VERSION 1
	22
	23	enum {
	24	NSMPROC_NULL,
	25	NSMPROC_STAT,
	26	NSMPROC_MON,
	27	NSMPROC_UNMON,
	28	NSMPROC_UNMON_ALL,
	29	NSMPROC_SIMU_CRASH,
	30	NSMPROC_NOTIFY,
	31	};
1da177e4	32
9c1bfd03 CL	33	struct nsm_args {
	34	__be32 addr; /* remote address */
	35	u32 prog; /* RPC callback info */
	36	u32 vers;
	37	u32 proc;
	38
	39	char *mon_name;
	40	};
	41
	42	struct nsm_res {
	43	u32 status;
	44	u32 state;
	45	};
	46
1da177e4 LT	47	static struct rpc_clnt * nsm_create(void);
	48
	49	static struct rpc_program nsm_program;
67c6d107 CL	50	static LIST_HEAD(nsm_handles);
67c6d107 CL	51	static DEFINE_SPINLOCK(nsm_lock);
1da177e4 LT	52
	53	/*
	54	* Local NSM state
	55	*/
460f5cac	56	int nsm_local_state;
1da177e4	57
67c6d107 CL	58	static void nsm_display_ipv4_address(const struct sockaddr sap, char buf,
	59	const size_t len)
	60	{
	61	const struct sockaddr_in sin = (struct sockaddr_in )sap;
	62	snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
	63	}
	64
	65	static void nsm_display_ipv6_address(const struct sockaddr sap, char buf,
	66	const size_t len)
	67	{
	68	const struct sockaddr_in6 sin6 = (struct sockaddr_in6 )sap;
	69
	70	if (ipv6_addr_v4mapped(&sin6->sin6_addr))
	71	snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]);
	72	else if (sin6->sin6_scope_id != 0)
	73	snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr,
	74	sin6->sin6_scope_id);
	75	else
	76	snprintf(buf, len, "%pI6", &sin6->sin6_addr);
	77	}
	78
	79	static void nsm_display_address(const struct sockaddr *sap,
	80	char *buf, const size_t len)
	81	{
	82	switch (sap->sa_family) {
	83	case AF_INET:
	84	nsm_display_ipv4_address(sap, buf, len);
	85	break;
	86	case AF_INET6:
	87	nsm_display_ipv6_address(sap, buf, len);
	88	break;
	89	default:
	90	snprintf(buf, len, "unsupported address family");
	91	break;
	92	}
	93	}
	94
1da177e4	95	/*
36e8e668	96	* Common procedure for NSMPROC_MON/NSMPROC_UNMON calls
1da177e4 LT	97	*/
1da177e4 LT	98	static int
9502c522	99	nsm_mon_unmon(struct nsm_handle nsm, u32 proc, struct nsm_res res)
1da177e4 LT	100	{
	101	struct rpc_clnt *clnt;
	102	int status;
a4846750 CL	103	struct nsm_args args = {
	104	.addr = nsm_addr_in(nsm)->sin_addr.s_addr,
	105	.prog = NLM_PROGRAM,
	106	.vers = 3,
	107	.proc = NLMPROC_NSM_NOTIFY,
29ed1407	108	.mon_name = nsm->sm_mon_name,
a4846750	109	};
dead28da CL	110	struct rpc_message msg = {
	111	.rpc_argp = &args,
	112	.rpc_resp = res,
	113	};
1da177e4 LT	114
	115	clnt = nsm_create();
	116	if (IS_ERR(clnt)) {
	117	status = PTR_ERR(clnt);
5acf4315 CL	118	dprintk("lockd: failed to create NSM upcall transport, "
5acf4315 CL	119	"status=%d\n", status);
1da177e4 LT	120	goto out;
	121	}
	122
1da177e4 LT	123	memset(res, 0, sizeof(*res));
1da177e4 LT	124
dead28da CL	125	msg.rpc_proc = &clnt->cl_procinfo[proc];
dead28da CL	126	status = rpc_call_sync(clnt, &msg, 0);
1da177e4	127	if (status < 0)
5acf4315 CL	128	dprintk("lockd: NSM upcall RPC failed, status=%d\n",
5acf4315 CL	129	status);
1da177e4 LT	130	else
1da177e4 LT	131	status = 0;
90c5755f	132	rpc_shutdown_client(clnt);
1da177e4 LT	133	out:
	134	return status;
	135	}
	136
1e49323c CL	137	/**
	138	* nsm_monitor - Notify a peer in case we reboot
	139	* @host: pointer to nlm_host of peer to notify
	140	*
	141	* If this peer is not already monitored, this function sends an
	142	* upcall to the local rpc.statd to record the name/address of
	143	* the peer to notify in case we reboot.
	144	*
	145	* Returns zero if the peer is monitored by the local rpc.statd;
	146	* otherwise a negative errno value is returned.
1da177e4	147	*/
1e49323c	148	int nsm_monitor(const struct nlm_host *host)
1da177e4	149	{
8dead0db	150	struct nsm_handle *nsm = host->h_nsmhandle;
1da177e4 LT	151	struct nsm_res res;
	152	int status;
	153
9fee4902	154	dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
8dead0db OK	155
8dead0db OK	156	if (nsm->sm_monitored)
977faf39	157	return 0;
1da177e4	158
29ed1407 CL	159	/*
	160	* Choose whether to record the caller_name or IP address of
	161	* this peer in the local rpc.statd's database.
	162	*/
	163	nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
	164
36e8e668	165	status = nsm_mon_unmon(nsm, NSMPROC_MON, &res);
5d254b11 CL	166	if (res.status != 0)
	167	status = -EIO;
	168	if (status < 0)
9fee4902	169	printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
1da177e4	170	else
8dead0db	171	nsm->sm_monitored = 1;
1da177e4 LT	172	return status;
	173	}
	174
356c3eb4 CL	175	/**
	176	* nsm_unmonitor - Unregister peer notification
	177	* @host: pointer to nlm_host of peer to stop monitoring
	178	*
	179	* If this peer is monitored, this function sends an upcall to
	180	* tell the local rpc.statd not to send this peer a notification
	181	* when we reboot.
1da177e4	182	*/
356c3eb4	183	void nsm_unmonitor(const struct nlm_host *host)
1da177e4	184	{
8dead0db	185	struct nsm_handle *nsm = host->h_nsmhandle;
1da177e4	186	struct nsm_res res;
356c3eb4	187	int status;
1da177e4	188
9502c522 OK	189	if (atomic_read(&nsm->sm_count) == 1
9502c522 OK	190	&& nsm->sm_monitored && !nsm->sm_sticky) {
9fee4902	191	dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
9502c522	192
36e8e668	193	status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res);
0c7aef45 CL	194	if (res.status != 0)
0c7aef45 CL	195	status = -EIO;
977faf39	196	if (status < 0)
9502c522	197	printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
9fee4902	198	nsm->sm_name);
9502c522 OK	199	else
9502c522 OK	200	nsm->sm_monitored = 0;
977faf39	201	}
1da177e4 LT	202	}
1da177e4 LT	203
67c6d107 CL	204	/**
	205	* nsm_find - Find or create a cached nsm_handle
	206	* @sap: pointer to socket address of handle to find
	207	* @salen: length of socket address
	208	* @hostname: pointer to C string containing hostname to find
	209	* @hostname_len: length of C string
	210	* @create: one means create new handle if not found in cache
	211	*
	212	* Behavior is modulated by the global nsm_use_hostnames variable
	213	* and by the @create argument.
	214	*
	215	* Returns a cached nsm_handle after bumping its ref count, or if
	216	* @create is set, returns a fresh nsm_handle if a handle that
	217	* matches @sap and/or @hostname cannot be found in the handle cache.
	218	* Returns NULL if an error occurs.
	219	*/
	220	struct nsm_handle nsm_find(const struct sockaddr sap, const size_t salen,
	221	const char *hostname, const size_t hostname_len,
	222	const int create)
	223	{
	224	struct nsm_handle *nsm = NULL;
	225	struct nsm_handle *pos;
	226
	227	if (!sap)
	228	return NULL;
	229
	230	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
	231	if (printk_ratelimit()) {
	232	printk(KERN_WARNING "Invalid hostname \"%.*s\" "
	233	"in NFS lock request\n",
	234	(int)hostname_len, hostname);
	235	}
	236	return NULL;
	237	}
	238
	239	retry:
	240	spin_lock(&nsm_lock);
	241	list_for_each_entry(pos, &nsm_handles, sm_link) {
	242
	243	if (hostname && nsm_use_hostnames) {
	244	if (strlen(pos->sm_name) != hostname_len
	245	\|\| memcmp(pos->sm_name, hostname, hostname_len))
	246	continue;
	247	} else if (!nlm_cmp_addr(nsm_addr(pos), sap))
	248	continue;
	249	atomic_inc(&pos->sm_count);
	250	kfree(nsm);
	251	nsm = pos;
	252	goto found;
	253	}
	254	if (nsm) {
	255	list_add(&nsm->sm_link, &nsm_handles);
	256	goto found;
	257	}
	258	spin_unlock(&nsm_lock);
	259
	260	if (!create)
	261	return NULL;
	262
	263	nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
	264	if (nsm == NULL)
	265	return NULL;
	266
	267	memcpy(nsm_addr(nsm), sap, salen);
268	nsm->sm_addrlen = salen;
269	nsm->sm_name = (char *) (nsm + 1);
270	memcpy(nsm->sm_name, hostname, hostname_len);
271	nsm->sm_name[hostname_len] = '\0';
272	nsm_display_address((struct sockaddr *)&nsm->sm_addr,
273	nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
274	atomic_set(&nsm->sm_count, 1);
275	goto retry;
276
277	found:
278	spin_unlock(&nsm_lock);
279	return nsm;
280	}
281
282	/**
283	* nsm_release - Release an NSM handle
284	* @nsm: pointer to handle to be released
285	*
286	*/
287	void nsm_release(struct nsm_handle *nsm)
288	{
289	if (!nsm)
290	return;
291	if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
292	list_del(&nsm->sm_link);
293	spin_unlock(&nsm_lock);
294	kfree(nsm);
295	}
296	}
297
1da177e4 LT	298	/*
	299	* Create NSM client for the local host
	300	*/
	301	static struct rpc_clnt *
	302	nsm_create(void)
	303	{
e1ec7892 CL	304	struct sockaddr_in sin = {
	305	.sin_family = AF_INET,
	306	.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
	307	.sin_port = 0,
	308	};
	309	struct rpc_create_args args = {
0896a725	310	.protocol = XPRT_TRANSPORT_UDP,
e1ec7892 CL	311	.address = (struct sockaddr *)&sin,
	312	.addrsize = sizeof(sin),
	313	.servername = "localhost",
	314	.program = &nsm_program,
36e8e668	315	.version = NSM_VERSION,
e1ec7892	316	.authflavor = RPC_AUTH_NULL,
e1ec7892 CL	317	};
	318
	319	return rpc_create(&args);
1da177e4 LT	320	}
	321
	322	/*
	323	* XDR functions for NSM.
2ca7754d CL	324	*
	325	* See http://www.opengroup.org/ for details on the Network
	326	* Status Monitor wire protocol.
1da177e4 LT	327	*/
1da177e4 LT	328
03eb1dcb	329	static int encode_nsm_string(struct xdr_stream xdr, const char string)
099bd05f	330	{
03eb1dcb CL	331	const u32 len = strlen(string);
	332	__be32 *p;
	333
	334	if (unlikely(len > SM_MAXSTRLEN))
	335	return -EIO;
	336	p = xdr_reserve_space(xdr, sizeof(u32) + len);
	337	if (unlikely(p == NULL))
	338	return -EIO;
	339	xdr_encode_opaque(p, string, len);
	340	return 0;
099bd05f CL	341	}
099bd05f CL	342
49695174 CL	343	/*
49695174 CL	344	* "mon_name" specifies the host to be monitored.
49695174	345	*/
03eb1dcb	346	static int encode_mon_name(struct xdr_stream xdr, const struct nsm_args argp)
49695174	347	{
03eb1dcb	348	return encode_nsm_string(xdr, argp->mon_name);
49695174 CL	349	}
49695174 CL	350
850c95fd CL	351	/*
	352	* The "my_id" argument specifies the hostname and RPC procedure
	353	* to be called when the status manager receives notification
36e8e668	354	* (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
850c95fd CL	355	* has changed.
850c95fd CL	356	*/
03eb1dcb	357	static int encode_my_id(struct xdr_stream xdr, const struct nsm_args argp)
850c95fd	358	{
03eb1dcb CL	359	int status;
	360	__be32 *p;
	361
	362	status = encode_nsm_string(xdr, utsname()->nodename);
	363	if (unlikely(status != 0))
	364	return status;
	365	p = xdr_reserve_space(xdr, 3 * sizeof(u32));
	366	if (unlikely(p == NULL))
	367	return -EIO;
850c95fd CL	368	*p++ = htonl(argp->prog);
	369	*p++ = htonl(argp->vers);
	370	*p++ = htonl(argp->proc);
03eb1dcb	371	return 0;
850c95fd CL	372	}
850c95fd CL	373
ea72a7f1 CL	374	/*
ea72a7f1 CL	375	* The "mon_id" argument specifies the non-private arguments
36e8e668	376	* of an NSMPROC_MON or NSMPROC_UNMON call.
ea72a7f1	377	*/
03eb1dcb	378	static int encode_mon_id(struct xdr_stream xdr, const struct nsm_args argp)
ea72a7f1	379	{
03eb1dcb	380	int status;
ea72a7f1	381
03eb1dcb CL	382	status = encode_mon_name(xdr, argp);
	383	if (unlikely(status != 0))
	384	return status;
	385	return encode_my_id(xdr, argp);
ea72a7f1 CL	386	}
ea72a7f1 CL	387
0490a54a CL	388	/*
0490a54a CL	389	* The "priv" argument may contain private information required
36e8e668 CL	390	* by the NSMPROC_MON call. This information will be supplied in the
36e8e668 CL	391	* NLMPROC_SM_NOTIFY call.
0490a54a CL	392	*
	393	* Linux provides the raw IP address of the monitored host,
	394	* left in network byte order.
	395	*/
03eb1dcb	396	static int encode_priv(struct xdr_stream xdr, const struct nsm_args argp)
0490a54a	397	{
03eb1dcb CL	398	__be32 *p;
	399
	400	p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
	401	if (unlikely(p == NULL))
	402	return -EIO;
0490a54a CL	403	*p++ = argp->addr;
	404	*p++ = 0;
	405	*p++ = 0;
	406	*p++ = 0;
03eb1dcb	407	return 0;
0490a54a CL	408	}
0490a54a CL	409
03eb1dcb CL	410	static int xdr_enc_mon(struct rpc_rqst req, __be32 p,
03eb1dcb CL	411	const struct nsm_args *argp)
1da177e4	412	{
03eb1dcb CL	413	struct xdr_stream xdr;
03eb1dcb CL	414	int status;
0490a54a	415
03eb1dcb CL	416	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	417	status = encode_mon_id(&xdr, argp);
	418	if (unlikely(status))
	419	return status;
	420	return encode_priv(&xdr, argp);
1da177e4 LT	421	}
1da177e4 LT	422
03eb1dcb CL	423	static int xdr_enc_unmon(struct rpc_rqst req, __be32 p,
03eb1dcb CL	424	const struct nsm_args *argp)
1da177e4	425	{
03eb1dcb CL	426	struct xdr_stream xdr;
	427
	428	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	429	return encode_mon_id(&xdr, argp);
1da177e4 LT	430	}
1da177e4 LT	431
03eb1dcb CL	432	static int xdr_dec_stat_res(struct rpc_rqst rqstp, __be32 p,
03eb1dcb CL	433	struct nsm_res *resp)
1da177e4	434	{
03eb1dcb CL	435	struct xdr_stream xdr;
	436
	437	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	438	p = xdr_inline_decode(&xdr, 2 * sizeof(u32));
	439	if (unlikely(p == NULL))
	440	return -EIO;
1da177e4	441	resp->status = ntohl(*p++);
03eb1dcb CL	442	resp->state = ntohl(*p);
	443
	444	dprintk("lockd: xdr_dec_stat_res status %d state %d\n",
1da177e4 LT	445	resp->status, resp->state);
	446	return 0;
	447	}
	448
03eb1dcb CL	449	static int xdr_dec_stat(struct rpc_rqst rqstp, __be32 p,
03eb1dcb CL	450	struct nsm_res *resp)
1da177e4	451	{
03eb1dcb CL	452	struct xdr_stream xdr;
	453
	454	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	455	p = xdr_inline_decode(&xdr, sizeof(u32));
	456	if (unlikely(p == NULL))
	457	return -EIO;
	458	resp->state = ntohl(*p);
	459
	460	dprintk("lockd: xdr_dec_stat state %d\n", resp->state);
1da177e4 LT	461	return 0;
	462	}
	463
	464	#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
2ca7754d CL	465	#define SM_my_id_sz (SM_my_name_sz+3)
	466	#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
	467	#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
0490a54a CL	468	#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
0490a54a CL	469	#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
1da177e4 LT	470	#define SM_monres_sz 2
	471	#define SM_unmonres_sz 1
	472
1da177e4	473	static struct rpc_procinfo nsm_procedures[] = {
36e8e668 CL	474	[NSMPROC_MON] = {
36e8e668 CL	475	.p_proc = NSMPROC_MON,
03eb1dcb CL	476	.p_encode = (kxdrproc_t)xdr_enc_mon,
03eb1dcb CL	477	.p_decode = (kxdrproc_t)xdr_dec_stat_res,
2bea90d4 CL	478	.p_arglen = SM_mon_sz,
2bea90d4 CL	479	.p_replen = SM_monres_sz,
36e8e668	480	.p_statidx = NSMPROC_MON,
cc0175c1	481	.p_name = "MONITOR",
1da177e4	482	},
36e8e668 CL	483	[NSMPROC_UNMON] = {
36e8e668 CL	484	.p_proc = NSMPROC_UNMON,
03eb1dcb CL	485	.p_encode = (kxdrproc_t)xdr_enc_unmon,
03eb1dcb CL	486	.p_decode = (kxdrproc_t)xdr_dec_stat,
2bea90d4 CL	487	.p_arglen = SM_mon_id_sz,
2bea90d4 CL	488	.p_replen = SM_unmonres_sz,
36e8e668	489	.p_statidx = NSMPROC_UNMON,
cc0175c1	490	.p_name = "UNMONITOR",
1da177e4 LT	491	},
	492	};
	493
	494	static struct rpc_version nsm_version1 = {
e8c96f8c TK	495	.number = 1,
e8c96f8c TK	496	.nrprocs = ARRAY_SIZE(nsm_procedures),
1da177e4 LT	497	.procs = nsm_procedures
	498	};
	499
	500	static struct rpc_version * nsm_version[] = {
	501	[1] = &nsm_version1,
	502	};
	503
	504	static struct rpc_stat nsm_stats;
	505
	506	static struct rpc_program nsm_program = {
	507	.name = "statd",
36e8e668	508	.number = NSM_PROGRAM,
e8c96f8c	509	.nrvers = ARRAY_SIZE(nsm_version),
1da177e4 LT	510	.version = nsm_version,
	511	.stats = &nsm_stats
	512	};