xref: /openbmc/linux/fs/lockd/mon.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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>
13 #include <linux/sunrpc/svc.h>
14 #include <linux/lockd/lockd.h>
15 #include <linux/lockd/sm_inter.h>
16 
17 
18 #define NLMDBG_FACILITY		NLMDBG_MONITOR
19 
20 static struct rpc_clnt *	nsm_create(void);
21 
22 static struct rpc_program	nsm_program;
23 
24 /*
25  * Local NSM state
26  */
27 u32				nsm_local_state;
28 
29 /*
30  * Common procedure for SM_MON/SM_UNMON calls
31  */
32 static int
33 nsm_mon_unmon(struct nlm_host *host, u32 proc, struct nsm_res *res)
34 {
35 	struct rpc_clnt	*clnt;
36 	int		status;
37 	struct nsm_args	args;
38 
39 	clnt = nsm_create();
40 	if (IS_ERR(clnt)) {
41 		status = PTR_ERR(clnt);
42 		goto out;
43 	}
44 
45 	args.addr = host->h_addr.sin_addr.s_addr;
46 	args.proto= (host->h_proto<<1) | host->h_server;
47 	args.prog = NLM_PROGRAM;
48 	args.vers = host->h_version;
49 	args.proc = NLMPROC_NSM_NOTIFY;
50 	memset(res, 0, sizeof(*res));
51 
52 	status = rpc_call(clnt, proc, &args, res, 0);
53 	if (status < 0)
54 		printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n",
55 			status);
56 	else
57 		status = 0;
58  out:
59 	return status;
60 }
61 
62 /*
63  * Set up monitoring of a remote host
64  */
65 int
66 nsm_monitor(struct nlm_host *host)
67 {
68 	struct nsm_res	res;
69 	int		status;
70 
71 	dprintk("lockd: nsm_monitor(%s)\n", host->h_name);
72 
73 	status = nsm_mon_unmon(host, SM_MON, &res);
74 
75 	if (status < 0 || res.status != 0)
76 		printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name);
77 	else
78 		host->h_monitored = 1;
79 	return status;
80 }
81 
82 /*
83  * Cease to monitor remote host
84  */
85 int
86 nsm_unmonitor(struct nlm_host *host)
87 {
88 	struct nsm_res	res;
89 	int		status;
90 
91 	dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name);
92 
93 	status = nsm_mon_unmon(host, SM_UNMON, &res);
94 	if (status < 0)
95 		printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", host->h_name);
96 	else
97 		host->h_monitored = 0;
98 	return status;
99 }
100 
101 /*
102  * Create NSM client for the local host
103  */
104 static struct rpc_clnt *
105 nsm_create(void)
106 {
107 	struct rpc_xprt		*xprt;
108 	struct rpc_clnt		*clnt;
109 	struct sockaddr_in	sin;
110 
111 	sin.sin_family = AF_INET;
112 	sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
113 	sin.sin_port = 0;
114 
115 	xprt = xprt_create_proto(IPPROTO_UDP, &sin, NULL);
116 	if (IS_ERR(xprt))
117 		return (struct rpc_clnt *)xprt;
118 	xprt->resvport = 1;	/* NSM requires a reserved port */
119 
120 	clnt = rpc_create_client(xprt, "localhost",
121 				&nsm_program, SM_VERSION,
122 				RPC_AUTH_NULL);
123 	if (IS_ERR(clnt))
124 		goto out_err;
125 	clnt->cl_softrtry = 1;
126 	clnt->cl_chatty   = 1;
127 	clnt->cl_oneshot  = 1;
128 	return clnt;
129 
130 out_err:
131 	return clnt;
132 }
133 
134 /*
135  * XDR functions for NSM.
136  */
137 
138 static u32 *
139 xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
140 {
141 	char	buffer[20];
142 
143 	/*
144 	 * Use the dotted-quad IP address of the remote host as
145 	 * identifier. Linux statd always looks up the canonical
146 	 * hostname first for whatever remote hostname it receives,
147 	 * so this works alright.
148 	 */
149 	sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
150 	if (!(p = xdr_encode_string(p, buffer))
151 	 || !(p = xdr_encode_string(p, system_utsname.nodename)))
152 		return ERR_PTR(-EIO);
153 	*p++ = htonl(argp->prog);
154 	*p++ = htonl(argp->vers);
155 	*p++ = htonl(argp->proc);
156 
157 	return p;
158 }
159 
160 static int
161 xdr_encode_mon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
162 {
163 	p = xdr_encode_common(rqstp, p, argp);
164 	if (IS_ERR(p))
165 		return PTR_ERR(p);
166 	*p++ = argp->addr;
167 	*p++ = argp->vers;
168 	*p++ = argp->proto;
169 	*p++ = 0;
170 	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
171 	return 0;
172 }
173 
174 static int
175 xdr_encode_unmon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
176 {
177 	p = xdr_encode_common(rqstp, p, argp);
178 	if (IS_ERR(p))
179 		return PTR_ERR(p);
180 	rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
181 	return 0;
182 }
183 
184 static int
185 xdr_decode_stat_res(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
186 {
187 	resp->status = ntohl(*p++);
188 	resp->state = ntohl(*p++);
189 	dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
190 			resp->status, resp->state);
191 	return 0;
192 }
193 
194 static int
195 xdr_decode_stat(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
196 {
197 	resp->state = ntohl(*p++);
198 	return 0;
199 }
200 
201 #define SM_my_name_sz	(1+XDR_QUADLEN(SM_MAXSTRLEN))
202 #define SM_my_id_sz	(3+1+SM_my_name_sz)
203 #define SM_mon_id_sz	(1+XDR_QUADLEN(20)+SM_my_id_sz)
204 #define SM_mon_sz	(SM_mon_id_sz+4)
205 #define SM_monres_sz	2
206 #define SM_unmonres_sz	1
207 
208 #ifndef MAX
209 # define MAX(a, b)	(((a) > (b))? (a) : (b))
210 #endif
211 
212 static struct rpc_procinfo	nsm_procedures[] = {
213 [SM_MON] = {
214 		.p_proc		= SM_MON,
215 		.p_encode	= (kxdrproc_t) xdr_encode_mon,
216 		.p_decode	= (kxdrproc_t) xdr_decode_stat_res,
217 		.p_bufsiz	= MAX(SM_mon_sz, SM_monres_sz) << 2,
218 	},
219 [SM_UNMON] = {
220 		.p_proc		= SM_UNMON,
221 		.p_encode	= (kxdrproc_t) xdr_encode_unmon,
222 		.p_decode	= (kxdrproc_t) xdr_decode_stat,
223 		.p_bufsiz	= MAX(SM_mon_id_sz, SM_unmonres_sz) << 2,
224 	},
225 };
226 
227 static struct rpc_version	nsm_version1 = {
228 		.number		= 1,
229 		.nrprocs	= sizeof(nsm_procedures)/sizeof(nsm_procedures[0]),
230 		.procs		= nsm_procedures
231 };
232 
233 static struct rpc_version *	nsm_version[] = {
234 	[1] = &nsm_version1,
235 };
236 
237 static struct rpc_stat		nsm_stats;
238 
239 static struct rpc_program	nsm_program = {
240 		.name		= "statd",
241 		.number		= SM_PROGRAM,
242 		.nrvers		= sizeof(nsm_version)/sizeof(nsm_version[0]),
243 		.version	= nsm_version,
244 		.stats		= &nsm_stats
245 };
246