1 /*
2  * linux/net/sunrpc/pmap.c
3  *
4  * Portmapper client.
5  *
6  * FIXME: In a secure environment, we may want to use an authentication
7  * flavor other than AUTH_NULL.
8  *
9  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
10  */
11 
12 #include <linux/config.h>
13 #include <linux/types.h>
14 #include <linux/socket.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/uio.h>
18 #include <linux/in.h>
19 #include <linux/sunrpc/clnt.h>
20 #include <linux/sunrpc/xprt.h>
21 #include <linux/sunrpc/sched.h>
22 
23 #ifdef RPC_DEBUG
24 # define RPCDBG_FACILITY	RPCDBG_PMAP
25 #endif
26 
27 #define PMAP_SET		1
28 #define PMAP_UNSET		2
29 #define PMAP_GETPORT		3
30 
31 static struct rpc_clnt *	pmap_create(char *, struct sockaddr_in *, int);
32 static void			pmap_getport_done(struct rpc_task *);
33 extern struct rpc_program	pmap_program;
34 static spinlock_t		pmap_lock = SPIN_LOCK_UNLOCKED;
35 
36 /*
37  * Obtain the port for a given RPC service on a given host. This one can
38  * be called for an ongoing RPC request.
39  */
40 void
rpc_getport(struct rpc_task * task,struct rpc_clnt * clnt)41 rpc_getport(struct rpc_task *task, struct rpc_clnt *clnt)
42 {
43 	struct rpc_portmap *map = &clnt->cl_pmap;
44 	struct sockaddr_in *sap = &clnt->cl_xprt->addr;
45 	struct rpc_message msg = { PMAP_GETPORT, map, &clnt->cl_port, NULL };
46 	struct rpc_clnt	*pmap_clnt;
47 	struct rpc_task	*child;
48 
49 	dprintk("RPC: %4d rpc_getport(%s, %d, %d, %d)\n",
50 			task->tk_pid, clnt->cl_server,
51 			map->pm_prog, map->pm_vers, map->pm_prot);
52 
53 	spin_lock(&pmap_lock);
54 	if (clnt->cl_binding) {
55 		rpc_sleep_on(&clnt->cl_bindwait, task, NULL, 0);
56 		spin_unlock(&pmap_lock);
57 		return;
58 	}
59 	clnt->cl_binding = 1;
60 	spin_unlock(&pmap_lock);
61 
62 	task->tk_status = -EACCES; /* why set this? returns -EIO below */
63 	if (!(pmap_clnt = pmap_create(clnt->cl_server, sap, map->pm_prot)))
64 		goto bailout;
65 	task->tk_status = 0;
66 
67 	/*
68 	 * Note: rpc_new_child will release client after a failure.
69 	 */
70 	if (!(child = rpc_new_child(pmap_clnt, task)))
71 		goto bailout;
72 
73 	/* Setup the call info struct */
74 	rpc_call_setup(child, &msg, 0);
75 
76 	/* ... and run the child task */
77 	rpc_run_child(task, child, pmap_getport_done);
78 	return;
79 
80 bailout:
81 	spin_lock(&pmap_lock);
82 	clnt->cl_binding = 0;
83 	rpc_wake_up(&clnt->cl_bindwait);
84 	spin_unlock(&pmap_lock);
85 	task->tk_status = -EIO;
86 	task->tk_action = NULL;
87 }
88 
89 #ifdef CONFIG_ROOT_NFS
90 int
rpc_getport_external(struct sockaddr_in * sin,__u32 prog,__u32 vers,int prot)91 rpc_getport_external(struct sockaddr_in *sin, __u32 prog, __u32 vers, int prot)
92 {
93 	struct rpc_portmap map = { prog, vers, prot, 0 };
94 	struct rpc_clnt	*pmap_clnt;
95 	char		hostname[32];
96 	int		status;
97 
98 	dprintk("RPC:      rpc_getport_external(%u.%u.%u.%u, %d, %d, %d)\n",
99 			NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot);
100 
101 	sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(sin->sin_addr.s_addr));
102 	if (!(pmap_clnt = pmap_create(hostname, sin, prot)))
103 		return -EACCES;
104 
105 	/* Setup the call info struct */
106 	status = rpc_call(pmap_clnt, PMAP_GETPORT, &map, &map.pm_port, 0);
107 
108 	if (status >= 0) {
109 		if (map.pm_port != 0)
110 			return map.pm_port;
111 		status = -EACCES;
112 	}
113 	return status;
114 }
115 #endif
116 
117 static void
pmap_getport_done(struct rpc_task * task)118 pmap_getport_done(struct rpc_task *task)
119 {
120 	struct rpc_clnt	*clnt = task->tk_client;
121 
122 	dprintk("RPC: %4d pmap_getport_done(status %d, port %d)\n",
123 			task->tk_pid, task->tk_status, clnt->cl_port);
124 	if (task->tk_status < 0) {
125 		/* Make the calling task exit with an error */
126 		task->tk_action = NULL;
127 	} else if (clnt->cl_port == 0) {
128 		/* Program not registered */
129 		task->tk_status = -EACCES;
130 		task->tk_action = NULL;
131 	} else {
132 		/* byte-swap port number first */
133 		clnt->cl_port = htons(clnt->cl_port);
134 		clnt->cl_xprt->addr.sin_port = clnt->cl_port;
135 	}
136 	spin_lock(&pmap_lock);
137 	clnt->cl_binding = 0;
138 	rpc_wake_up(&clnt->cl_bindwait);
139 	spin_unlock(&pmap_lock);
140 }
141 
142 /*
143  * Set or unset a port registration with the local portmapper.
144  * port == 0 means unregister, port != 0 means register.
145  */
146 int
rpc_register(u32 prog,u32 vers,int prot,unsigned short port,int * okay)147 rpc_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
148 {
149 	struct sockaddr_in	sin;
150 	struct rpc_portmap	map;
151 	struct rpc_clnt		*pmap_clnt;
152 	unsigned int		error = 0;
153 
154 	dprintk("RPC: registering (%d, %d, %d, %d) with portmapper.\n",
155 			prog, vers, prot, port);
156 
157 	sin.sin_family = AF_INET;
158 	sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
159 	if (!(pmap_clnt = pmap_create("localhost", &sin, IPPROTO_UDP))) {
160 		dprintk("RPC: couldn't create pmap client\n");
161 		return -EACCES;
162 	}
163 
164 	map.pm_prog = prog;
165 	map.pm_vers = vers;
166 	map.pm_prot = prot;
167 	map.pm_port = port;
168 
169 	error = rpc_call(pmap_clnt, port? PMAP_SET : PMAP_UNSET,
170 					&map, okay, 0);
171 
172 	if (error < 0) {
173 		printk(KERN_WARNING
174 			"RPC: failed to contact portmap (errno %d).\n",
175 			error);
176 	}
177 	dprintk("RPC: registration status %d/%d\n", error, *okay);
178 
179 	/* Client deleted automatically because cl_oneshot == 1 */
180 	return error;
181 }
182 
183 static struct rpc_clnt *
pmap_create(char * hostname,struct sockaddr_in * srvaddr,int proto)184 pmap_create(char *hostname, struct sockaddr_in *srvaddr, int proto)
185 {
186 	struct rpc_xprt	*xprt;
187 	struct rpc_clnt	*clnt;
188 
189 	/* printk("pmap: create xprt\n"); */
190 	if (!(xprt = xprt_create_proto(proto, srvaddr, NULL)))
191 		return NULL;
192 	xprt->addr.sin_port = htons(RPC_PMAP_PORT);
193 
194 	/* printk("pmap: create clnt\n"); */
195 	clnt = rpc_create_client(xprt, hostname,
196 				&pmap_program, RPC_PMAP_VERSION,
197 				RPC_AUTH_NULL);
198 	if (!clnt) {
199 		xprt_destroy(xprt);
200 	} else {
201 		clnt->cl_softrtry = 1;
202 		clnt->cl_chatty   = 1;
203 		clnt->cl_oneshot  = 1;
204 	}
205 	return clnt;
206 }
207 
208 /*
209  * XDR encode/decode functions for PMAP
210  */
211 static int
xdr_error(struct rpc_rqst * req,u32 * p,void * dummy)212 xdr_error(struct rpc_rqst *req, u32 *p, void *dummy)
213 {
214 	return -EIO;
215 }
216 
217 static int
xdr_encode_mapping(struct rpc_rqst * req,u32 * p,struct rpc_portmap * map)218 xdr_encode_mapping(struct rpc_rqst *req, u32 *p, struct rpc_portmap *map)
219 {
220 	dprintk("RPC: xdr_encode_mapping(%d, %d, %d, %d)\n",
221 		map->pm_prog, map->pm_vers, map->pm_prot, map->pm_port);
222 	*p++ = htonl(map->pm_prog);
223 	*p++ = htonl(map->pm_vers);
224 	*p++ = htonl(map->pm_prot);
225 	*p++ = htonl(map->pm_port);
226 
227 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
228 	return 0;
229 }
230 
231 static int
xdr_decode_port(struct rpc_rqst * req,u32 * p,unsigned short * portp)232 xdr_decode_port(struct rpc_rqst *req, u32 *p, unsigned short *portp)
233 {
234 	*portp = (unsigned short) ntohl(*p++);
235 	return 0;
236 }
237 
238 static int
xdr_decode_bool(struct rpc_rqst * req,u32 * p,unsigned int * boolp)239 xdr_decode_bool(struct rpc_rqst *req, u32 *p, unsigned int *boolp)
240 {
241 	*boolp = (unsigned int) ntohl(*p++);
242 	return 0;
243 }
244 
245 static struct rpc_procinfo	pmap_procedures[4] = {
246 	{ "pmap_null",
247 		(kxdrproc_t) xdr_error,
248 		(kxdrproc_t) xdr_error,	0, 0 },
249 	{ "pmap_set",
250 		(kxdrproc_t) xdr_encode_mapping,
251 		(kxdrproc_t) xdr_decode_bool, 4, 1 },
252 	{ "pmap_unset",
253 		(kxdrproc_t) xdr_encode_mapping,
254 		(kxdrproc_t) xdr_decode_bool, 4, 1 },
255 	{ "pmap_get",
256 		(kxdrproc_t) xdr_encode_mapping,
257 		(kxdrproc_t) xdr_decode_port, 4, 1 },
258 };
259 
260 static struct rpc_version	pmap_version2 = {
261 	2, 4, pmap_procedures
262 };
263 
264 static struct rpc_version *	pmap_version[] = {
265 	NULL,
266 	NULL,
267 	&pmap_version2,
268 };
269 
270 static struct rpc_stat		pmap_stats;
271 
272 struct rpc_program	pmap_program = {
273 	"portmap",
274 	RPC_PMAP_PROGRAM,
275 	sizeof(pmap_version)/sizeof(pmap_version[0]),
276 	pmap_version,
277 	&pmap_stats,
278 };
279