xref: /netbsd-src/sys/fs/nfs/common/krpc_subr.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd Exp 	*/
2 
3 /*-
4  * Copyright (c) 1995 Gordon Ross, Adam Glass
5  * Copyright (c) 1992 Regents of the University of California.
6  * All rights reserved.
7  *
8  * This software was developed by the Computer Systems Engineering group
9  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
10  * contributed to Berkeley.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Lawrence Berkeley Laboratory and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  * partially based on:
41  *      libnetboot/rpc.c
42  *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
43  */
44 
45 #include <sys/cdefs.h>
46 /* __FBSDID("FreeBSD: head/sys/nfs/krpc_subr.c 248207 2013-03-12 13:42:47Z glebius "); */
47 __RCSID("$NetBSD: krpc_subr.c,v 1.1.1.1 2013/09/30 07:19:32 dholland Exp $");
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/jail.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/proc.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
57 #include <sys/uio.h>
58 
59 #include <net/if.h>
60 #include <net/vnet.h>
61 
62 #include <netinet/in.h>
63 
64 #include <rpc/types.h>
65 #include <rpc/auth.h>
66 #include <rpc/rpc_msg.h>
67 #include <nfs/krpc.h>
68 #include <nfs/xdr_subs.h>
69 
70 /*
71  * Kernel support for Sun RPC
72  *
73  * Used currently for bootstrapping in nfs diskless configurations.
74  */
75 
76 /*
77  * Generic RPC headers
78  */
79 
80 struct auth_info {
81 	u_int32_t 	authtype;	/* auth type */
82 	u_int32_t	authlen;	/* auth length */
83 };
84 
85 struct auth_unix {
86 	int32_t   ua_time;
87 	int32_t   ua_hostname;	/* null */
88 	int32_t   ua_uid;
89 	int32_t   ua_gid;
90 	int32_t   ua_gidlist;	/* null */
91 };
92 
93 struct krpc_call {
94 	u_int32_t	rp_xid;		/* request transaction id */
95 	int32_t 	rp_direction;	/* call direction (0) */
96 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
97 	u_int32_t	rp_prog;	/* program */
98 	u_int32_t	rp_vers;	/* version */
99 	u_int32_t	rp_proc;	/* procedure */
100 	struct	auth_info rpc_auth;
101 	struct	auth_unix rpc_unix;
102 	struct	auth_info rpc_verf;
103 };
104 
105 struct krpc_reply {
106 	u_int32_t rp_xid;		/* request transaction id */
107 	int32_t  rp_direction;		/* call direction (1) */
108 	int32_t  rp_astatus;		/* accept status (0: accepted) */
109 	union {
110 		u_int32_t rpu_errno;
111 		struct {
112 			struct auth_info rok_auth;
113 			u_int32_t	rok_status;
114 		} rpu_rok;
115 	} rp_u;
116 };
117 #define rp_errno  rp_u.rpu_errno
118 #define rp_auth   rp_u.rpu_rok.rok_auth
119 #define rp_status rp_u.rpu_rok.rok_status
120 
121 #define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
122 
123 /*
124  * What is the longest we will wait before re-sending a request?
125  * Note this is also the frequency of "RPC timeout" messages.
126  * The re-send loop count sup linearly to this maximum, so the
127  * first complaint will happen after (1+2+3+4+5)=15 seconds.
128  */
129 #define	MAX_RESEND_DELAY 5	/* seconds */
130 
131 /*
132  * Call portmap to lookup a port number for a particular rpc program
133  * Returns non-zero error on failure.
134  */
135 int
136 krpc_portmap(struct sockaddr_in *sin, u_int prog, u_int vers, u_int16_t *portp,
137     struct thread *td)
138 {
139 	struct sdata {
140 		u_int32_t prog;		/* call program */
141 		u_int32_t vers;		/* call version */
142 		u_int32_t proto;	/* call protocol */
143 		u_int32_t port;		/* call port (unused) */
144 	} *sdata;
145 	struct rdata {
146 		u_int16_t pad;
147 		u_int16_t port;
148 	} *rdata;
149 	struct mbuf *m;
150 	int error;
151 
152 	/* The portmapper port is fixed. */
153 	if (prog == PMAPPROG) {
154 		*portp = htons(PMAPPORT);
155 		return 0;
156 	}
157 
158 	m = m_get(M_WAITOK, MT_DATA);
159 	sdata = mtod(m, struct sdata *);
160 	m->m_len = sizeof(*sdata);
161 
162 	/* Do the RPC to get it. */
163 	sdata->prog = txdr_unsigned(prog);
164 	sdata->vers = txdr_unsigned(vers);
165 	sdata->proto = txdr_unsigned(IPPROTO_UDP);
166 	sdata->port = 0;
167 
168 	sin->sin_port = htons(PMAPPORT);
169 	error = krpc_call(sin, PMAPPROG, PMAPVERS,
170 					  PMAPPROC_GETPORT, &m, NULL, td);
171 	if (error)
172 		return error;
173 
174 	if (m->m_len < sizeof(*rdata)) {
175 		m = m_pullup(m, sizeof(*rdata));
176 		if (m == NULL)
177 			return ENOBUFS;
178 	}
179 	rdata = mtod(m, struct rdata *);
180 	*portp = rdata->port;
181 
182 	m_freem(m);
183 	return 0;
184 }
185 
186 /*
187  * Do a remote procedure call (RPC) and wait for its reply.
188  * If from_p is non-null, then we are doing broadcast, and
189  * the address from whence the response came is saved there.
190  */
191 int
192 krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
193     struct mbuf **data, struct sockaddr **from_p, struct thread *td)
194 {
195 	struct socket *so;
196 	struct sockaddr_in *sin, ssin;
197 	struct sockaddr *from;
198 	struct mbuf *m, *nam, *mhead;
199 	struct krpc_call *call;
200 	struct krpc_reply *reply;
201 	struct sockopt sopt;
202 	struct timeval tv;
203 	struct uio auio;
204 	int error, rcvflg, timo, secs, len;
205 	static u_int32_t xid = ~0xFF;
206 	u_int16_t tport;
207 	u_int32_t saddr;
208 
209 	/*
210 	 * Validate address family.
211 	 * Sorry, this is INET specific...
212 	 */
213 	if (sa->sin_family != AF_INET)
214 		return (EAFNOSUPPORT);
215 
216 	/* Free at end if not null. */
217 	nam = mhead = NULL;
218 	from = NULL;
219 
220 	/*
221 	 * Create socket and set its recieve timeout.
222 	 */
223 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td->td_ucred, td)))
224 		goto out;
225 
226 	tv.tv_sec = 1;
227 	tv.tv_usec = 0;
228 	bzero(&sopt, sizeof sopt);
229 	sopt.sopt_dir = SOPT_SET;
230 	sopt.sopt_level = SOL_SOCKET;
231 	sopt.sopt_name = SO_RCVTIMEO;
232 	sopt.sopt_val = &tv;
233 	sopt.sopt_valsize = sizeof tv;
234 
235 	if ((error = sosetopt(so, &sopt)) != 0)
236 		goto out;
237 
238 	/*
239 	 * Enable broadcast if necessary.
240 	 */
241 	if (from_p) {
242 		int on = 1;
243 		sopt.sopt_name = SO_BROADCAST;
244 		sopt.sopt_val = &on;
245 		sopt.sopt_valsize = sizeof on;
246 		if ((error = sosetopt(so, &sopt)) != 0)
247 			goto out;
248 	}
249 
250 	/*
251 	 * Bind the local endpoint to a reserved port,
252 	 * because some NFS servers refuse requests from
253 	 * non-reserved (non-privileged) ports.
254 	 */
255 	sin = &ssin;
256 	bzero(sin, sizeof *sin);
257 	sin->sin_len = sizeof(*sin);
258 	sin->sin_family = AF_INET;
259 	sin->sin_addr.s_addr = INADDR_ANY;
260 	tport = IPPORT_RESERVED;
261 	do {
262 		tport--;
263 		sin->sin_port = htons(tport);
264 		error = sobind(so, (struct sockaddr *)sin, td);
265 	} while (error == EADDRINUSE &&
266 			 tport > IPPORT_RESERVED / 2);
267 	if (error) {
268 		printf("bind failed\n");
269 		goto out;
270 	}
271 
272 	/*
273 	 * Setup socket address for the server.
274 	 */
275 
276 	/*
277 	 * Prepend RPC message header.
278 	 */
279 	mhead = m_gethdr(M_WAITOK, MT_DATA);
280 	mhead->m_next = *data;
281 	call = mtod(mhead, struct krpc_call *);
282 	mhead->m_len = sizeof(*call);
283 	bzero((caddr_t)call, sizeof(*call));
284 	/* rpc_call part */
285 	xid++;
286 	call->rp_xid = txdr_unsigned(xid);
287 	/* call->rp_direction = 0; */
288 	call->rp_rpcvers = txdr_unsigned(2);
289 	call->rp_prog = txdr_unsigned(prog);
290 	call->rp_vers = txdr_unsigned(vers);
291 	call->rp_proc = txdr_unsigned(func);
292 	/* rpc_auth part (auth_unix as root) */
293 	call->rpc_auth.authtype = txdr_unsigned(AUTH_UNIX);
294 	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
295 	/* rpc_verf part (auth_null) */
296 	call->rpc_verf.authtype = 0;
297 	call->rpc_verf.authlen  = 0;
298 
299 	/*
300 	 * Setup packet header
301 	 */
302 	m_fixhdr(mhead);
303 	mhead->m_pkthdr.rcvif = NULL;
304 
305 	/*
306 	 * Send it, repeatedly, until a reply is received,
307 	 * but delay each re-send by an increasing amount.
308 	 * If the delay hits the maximum, start complaining.
309 	 */
310 	timo = 0;
311 	for (;;) {
312 		/* Send RPC request (or re-send). */
313 		m = m_copym(mhead, 0, M_COPYALL, M_WAITOK);
314 		error = sosend(so, (struct sockaddr *)sa, NULL, m,
315 			       NULL, 0, td);
316 		if (error) {
317 			printf("krpc_call: sosend: %d\n", error);
318 			goto out;
319 		}
320 		m = NULL;
321 
322 		/* Determine new timeout. */
323 		if (timo < MAX_RESEND_DELAY)
324 			timo++;
325 		else {
326 			saddr = ntohl(sa->sin_addr.s_addr);
327 			printf("RPC timeout for server %d.%d.%d.%d\n",
328 			       (saddr >> 24) & 255,
329 			       (saddr >> 16) & 255,
330 			       (saddr >> 8) & 255,
331 			       saddr & 255);
332 		}
333 
334 		/*
335 		 * Wait for up to timo seconds for a reply.
336 		 * The socket receive timeout was set to 1 second.
337 		 */
338 		secs = timo;
339 		while (secs > 0) {
340 			if (from) {
341 				free(from, M_SONAME);
342 				from = NULL;
343 			}
344 			if (m) {
345 				m_freem(m);
346 				m = NULL;
347 			}
348 			bzero(&auio, sizeof(auio));
349 			auio.uio_resid = len = 1<<16;
350 			rcvflg = 0;
351 			error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
352 			if (error == EWOULDBLOCK) {
353 				secs--;
354 				continue;
355 			}
356 			if (error)
357 				goto out;
358 			len -= auio.uio_resid;
359 
360 			/* Does the reply contain at least a header? */
361 			if (len < MIN_REPLY_HDR)
362 				continue;
363 			if (m->m_len < MIN_REPLY_HDR)
364 				continue;
365 			reply = mtod(m, struct krpc_reply *);
366 
367 			/* Is it the right reply? */
368 			if (reply->rp_direction != txdr_unsigned(REPLY))
369 				continue;
370 
371 			if (reply->rp_xid != txdr_unsigned(xid))
372 				continue;
373 
374 			/* Was RPC accepted? (authorization OK) */
375 			if (reply->rp_astatus != 0) {
376 				error = fxdr_unsigned(u_int32_t, reply->rp_errno);
377 				printf("rpc denied, error=%d\n", error);
378 				continue;
379 			}
380 
381 			/* Did the call succeed? */
382 			if (reply->rp_status != 0) {
383 				error = fxdr_unsigned(u_int32_t, reply->rp_status);
384 				if (error == PROG_MISMATCH) {
385 				  error = EBADRPC;
386 				  goto out;
387 				}
388 				printf("rpc denied, status=%d\n", error);
389 				continue;
390 			}
391 
392 			goto gotreply;	/* break two levels */
393 
394 		} /* while secs */
395 	} /* forever send/receive */
396 
397 	error = ETIMEDOUT;
398 	goto out;
399 
400  gotreply:
401 
402 	/*
403 	 * Get RPC reply header into first mbuf,
404 	 * get its length, then strip it off.
405 	 */
406 	len = sizeof(*reply);
407 	if (m->m_len < len) {
408 		m = m_pullup(m, len);
409 		if (m == NULL) {
410 			error = ENOBUFS;
411 			goto out;
412 		}
413 	}
414 	reply = mtod(m, struct krpc_reply *);
415 	if (reply->rp_auth.authtype != 0) {
416 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
417 		len = (len + 3) & ~3; /* XXX? */
418 	}
419 	m_adj(m, len);
420 
421 	/* result */
422 	*data = m;
423 	if (from_p) {
424 		*from_p = from;
425 		from = NULL;
426 	}
427 
428  out:
429 	if (mhead) m_freem(mhead);
430 	if (from) free(from, M_SONAME);
431 	soclose(so);
432 	return error;
433 }
434 
435 /*
436  * eXternal Data Representation routines.
437  * (but with non-standard args...)
438  */
439 
440 /*
441  * String representation for RPC.
442  */
443 struct xdr_string {
444 	u_int32_t len;		/* length without null or padding */
445 	char data[4];	/* data (longer, of course) */
446     /* data is padded to a long-word boundary */
447 };
448 
449 struct mbuf *
450 xdr_string_encode(char *str, int len)
451 {
452 	struct mbuf *m;
453 	struct xdr_string *xs;
454 	int dlen;	/* padded string length */
455 	int mlen;	/* message length */
456 
457 	dlen = (len + 3) & ~3;
458 	mlen = dlen + 4;
459 
460 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
461 		return (NULL);
462 
463 	m = m_get2(mlen, M_WAITOK, MT_DATA, 0);
464 	xs = mtod(m, struct xdr_string *);
465 	m->m_len = mlen;
466 	xs->len = txdr_unsigned(len);
467 	bcopy(str, xs->data, len);
468 	return (m);
469 }
470