summaryrefslogtreecommitdiffstats
path: root/fs/lockd/mon.c
blob: e02a1a4dfced12a6e2248f9982c2bebee5f2aa12 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/*
 * 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/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
 */
u32				nsm_local_state;

/*
 * Common procedure for SM_MON/SM_UNMON calls
 */
static int
nsm_mon_unmon(struct nlm_host *host, 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;
	}

	args.addr = host->h_addr.sin_addr.s_addr;
	args.proto= (host->h_proto<<1) | host->h_server;
	args.prog = NLM_PROGRAM;
	args.vers = host->h_version;
	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;
 out:
	return status;
}

/*
 * Set up monitoring of a remote host
 */
int
nsm_monitor(struct nlm_host *host)
{
	struct nsm_res	res;
	int		status;

	dprintk("lockd: nsm_monitor(%s)\n", host->h_name);
	if (host->h_monitored)
		return 0;

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

	if (status < 0 || res.status != 0)
		printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name);
	else
		host->h_monitored = 1;
	return status;
}

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

	dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name);
	if (!host->h_monitored)
		return 0;
	host->h_monitored = 0;

	if (!host->h_killed) {
		status = nsm_mon_unmon(host, SM_UNMON, &res);
		if (status < 0)
			printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", host->h_name);
	}
	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	= IPPROTO_UDP,
		.address	= (struct sockaddr *)&sin,
		.addrsize	= sizeof(sin),
		.servername	= "localhost",
		.program	= &nsm_program,
		.version	= SM_VERSION,
		.authflavor	= RPC_AUTH_NULL,
		.flags		= (RPC_CLNT_CREATE_ONESHOT),
	};

	return rpc_create(&args);
}

/*
 * XDR functions for NSM.
 */

static u32 *
xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
{
	char	buffer[20];

	/*
	 * Use the dotted-quad IP address of the remote host as
	 * identifier. Linux statd always looks up the canonical
	 * hostname first for whatever remote hostname it receives,
	 * so this works alright.
	 */
	sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
	if (!(p = xdr_encode_string(p, buffer))
	 || !(p = xdr_encode_string(p, utsname()->nodename)))
		return ERR_PTR(-EIO);
	*p++ = htonl(argp->prog);
	*p++ = htonl(argp->vers);
	*p++ = htonl(argp->proc);

	return p;
}

static int
xdr_encode_mon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
{
	p = xdr_encode_common(rqstp, p, argp);
	if (IS_ERR(p))
		return PTR_ERR(p);
	*p++ = argp->addr;
	*p++ = argp->vers;
	*p++ = argp->proto;
	*p++ = 0;
	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
	return 0;
}

static int
xdr_encode_unmon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
{
	p = xdr_encode_common(rqstp, 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, u32 *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, u32 *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	(3+1+SM_my_name_sz)
#define SM_mon_id_sz	(1+XDR_QUADLEN(20)+SM_my_id_sz)
#define SM_mon_sz	(SM_mon_id_sz+4)
#define SM_monres_sz	2
#define SM_unmonres_sz	1

#ifndef MAX
# define MAX(a, b)	(((a) > (b))? (a) : (b))
#endif

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_bufsiz	= MAX(SM_mon_sz, SM_monres_sz) << 2,
		.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_bufsiz	= MAX(SM_mon_id_sz, SM_unmonres_sz) << 2,
		.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
};