xref: /netbsd/sys/nfs/krpc_subr.c (revision c4a72b64)
1 /*	$NetBSD: krpc_subr.c,v 1.26 2002/09/22 19:15:09 jdolecek 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 __KERNEL_RCSID(0, "$NetBSD: krpc_subr.c,v 1.26 2002/09/22 19:15:09 jdolecek Exp $");
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/ioctl.h>
51 #include <sys/proc.h>
52 #include <sys/mount.h>
53 #include <sys/mbuf.h>
54 #include <sys/reboot.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
57 
58 #include <netinet/in.h>
59 
60 #include <nfs/rpcv2.h>
61 #include <nfs/krpc.h>
62 #include <nfs/xdr_subs.h>
63 #include <nfs/nfsproto.h> /* XXX NFSX_V3FHMAX for next */
64 #include <nfs/nfs.h>
65 #include <nfs/nfsmount.h>
66 #include <nfs/nfsdiskless.h> /* XXX decl nfs_boot_sendrecv */
67 
68 /*
69  * Kernel support for Sun RPC
70  *
71  * Used currently for bootstrapping in nfs diskless configurations.
72  */
73 
74 /*
75  * Generic RPC headers
76  */
77 
78 struct auth_info {
79 	u_int32_t 	authtype;	/* auth type */
80 	u_int32_t	authlen;	/* auth length */
81 };
82 
83 struct auth_unix {
84 	int32_t   ua_time;
85 	int32_t   ua_hostname;	/* null */
86 	int32_t   ua_uid;
87 	int32_t   ua_gid;
88 	int32_t   ua_gidlist;	/* null */
89 };
90 
91 struct rpc_call {
92 	u_int32_t	rp_xid;		/* request transaction id */
93 	int32_t 	rp_direction;	/* call direction (0) */
94 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
95 	u_int32_t	rp_prog;	/* program */
96 	u_int32_t	rp_vers;	/* version */
97 	u_int32_t	rp_proc;	/* procedure */
98 	struct	auth_info rpc_auth;
99 	struct	auth_unix rpc_unix;
100 	struct	auth_info rpc_verf;
101 };
102 
103 struct rpc_reply {
104 	u_int32_t rp_xid;		/* request transaction id */
105 	int32_t  rp_direction;		/* call direction (1) */
106 	int32_t  rp_astatus;		/* accept status (0: accepted) */
107 	union {
108 		/* rejected */
109 		struct {
110 			u_int32_t rej_stat;
111 			u_int32_t rej_val1;
112 			u_int32_t rej_val2;
113 		} rpu_rej;
114 		/* accepted */
115 		struct {
116 			struct auth_info rok_auth;
117 			u_int32_t	rok_status;
118 		} rpu_rok;
119 	} rp_u;
120 };
121 #define rp_rstat  rp_u.rpu_rej.rej_stat
122 #define rp_auth   rp_u.rpu_rok.rok_auth
123 #define rp_status rp_u.rpu_rok.rok_status
124 
125 #define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
126 
127 static int krpccheck __P((struct mbuf*, void*));
128 
129 /*
130  * Call portmap to lookup a port number for a particular rpc program
131  * Returns non-zero error on failure.
132  */
133 int
134 krpc_portmap(sin,  prog, vers, proto, portp)
135 	struct sockaddr_in *sin;		/* server address */
136 	u_int prog, vers, proto;	/* host order */
137 	u_int16_t *portp;	/* network order */
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_WAIT, 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(proto);
166 	sdata->port = 0;
167 
168 	sin->sin_port = htons(PMAPPORT);
169 	error = krpc_call(sin, PMAPPROG, PMAPVERS,
170 					  PMAPPROC_GETPORT, &m, NULL);
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 static int krpccheck(m, context)
187 struct mbuf *m;
188 void *context;
189 {
190 	struct rpc_reply *reply;
191 
192 	/* Does the reply contain at least a header? */
193 	if (m->m_pkthdr.len < MIN_REPLY_HDR)
194 		return(-1);
195 	if (m->m_len < sizeof(struct rpc_reply)) {
196 		m = m_pullup(m, sizeof(struct rpc_reply));
197 		if (m == NULL)
198 			return(-1);
199 	}
200 	reply = mtod(m, struct rpc_reply *);
201 
202 	/* Is it the right reply? */
203 	if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
204 		return(-1);
205 
206 	if (reply->rp_xid != txdr_unsigned(*(u_int32_t*)context))
207 		return(-1);
208 
209 	return(0);
210 }
211 
212 /*
213  * Do a remote procedure call (RPC) and wait for its reply.
214  * If from_p is non-null, then we are doing broadcast, and
215  * the address from whence the response came is saved there.
216  */
217 int
218 krpc_call(sa, prog, vers, func, data, from_p)
219 	struct sockaddr_in *sa;
220 	u_int prog, vers, func;
221 	struct mbuf **data;	/* input/output */
222 	struct mbuf **from_p;	/* output */
223 {
224 	struct socket *so;
225 	struct sockaddr_in *sin;
226 	struct mbuf *m, *nam, *mhead, *from;
227 	struct rpc_call *call;
228 	struct rpc_reply *reply;
229 	int error, len;
230 	static u_int32_t xid = ~0xFF;
231 	u_int16_t tport;
232 
233 	/*
234 	 * Validate address family.
235 	 * Sorry, this is INET specific...
236 	 */
237 	if (sa->sin_family != AF_INET)
238 		return (EAFNOSUPPORT);
239 
240 	/* Free at end if not null. */
241 	nam = mhead = NULL;
242 	from = NULL;
243 
244 	/*
245 	 * Create socket and set its receive timeout.
246 	 */
247 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0)))
248 		goto out;
249 
250 	if ((error = nfs_boot_setrecvtimo(so)))
251 		goto out;
252 
253 	/*
254 	 * Enable broadcast if necessary.
255 	 */
256 	if (from_p) {
257 		if ((error = nfs_boot_enbroadcast(so)))
258 			goto out;
259 	}
260 
261 	/*
262 	 * Bind the local endpoint to a reserved port,
263 	 * because some NFS servers refuse requests from
264 	 * non-reserved (non-privileged) ports.
265 	 */
266 	tport = IPPORT_RESERVED;
267 	do {
268 		tport--;
269 		error = nfs_boot_sobind_ipport(so, tport);
270 	} while (error == EADDRINUSE &&
271 			 tport > IPPORT_RESERVED / 2);
272 	if (error) {
273 		printf("bind failed\n");
274 		goto out;
275 	}
276 
277 	/*
278 	 * Setup socket address for the server.
279 	 */
280 	nam = m_get(M_WAIT, MT_SONAME);
281 	sin = mtod(nam, struct sockaddr_in *);
282 	memcpy((caddr_t)sin, (caddr_t)sa,
283 		  (nam->m_len = sa->sin_len));
284 
285 	/*
286 	 * Prepend RPC message header.
287 	 */
288 	mhead = m_gethdr(M_WAIT, MT_DATA);
289 	mhead->m_next = *data;
290 	call = mtod(mhead, struct rpc_call *);
291 	mhead->m_len = sizeof(*call);
292 	memset((caddr_t)call, 0, sizeof(*call));
293 	/* rpc_call part */
294 	xid++;
295 	call->rp_xid = txdr_unsigned(xid);
296 	/* call->rp_direction = 0; */
297 	call->rp_rpcvers = txdr_unsigned(2);
298 	call->rp_prog = txdr_unsigned(prog);
299 	call->rp_vers = txdr_unsigned(vers);
300 	call->rp_proc = txdr_unsigned(func);
301 	/* rpc_auth part (auth_unix as root) */
302 	call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
303 	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
304 	/* rpc_verf part (auth_null) */
305 	call->rpc_verf.authtype = 0;
306 	call->rpc_verf.authlen  = 0;
307 
308 	/*
309 	 * Setup packet header
310 	 */
311 	len = 0;
312 	m = mhead;
313 	while (m) {
314 		len += m->m_len;
315 		m = m->m_next;
316 	}
317 	mhead->m_pkthdr.len = len;
318 	mhead->m_pkthdr.rcvif = NULL;
319 
320 	error = nfs_boot_sendrecv(so, nam, 0, mhead, krpccheck, &m, &from, &xid);
321 	if (error)
322 		goto out;
323 
324 	/* m_pullup() was done in krpccheck() */
325 	reply = mtod(m, struct rpc_reply *);
326 
327 	/* Was RPC accepted? (authorization OK) */
328 	if (reply->rp_astatus != 0) {
329 		/* Note: This is NOT an error code! */
330 		error = fxdr_unsigned(u_int32_t, reply->rp_rstat);
331 		switch (error) {
332 		    case RPC_MISMATCH:
333 			/* .re_status = RPC_VERSMISMATCH; */
334 			error = ERPCMISMATCH;
335 			break;
336 		    case RPC_AUTHERR:
337 			/* .re_status = RPC_AUTHERROR; */
338 			error = EAUTH;
339 			break;
340 		    default:
341 			/* unexpected */
342 			error = EBADRPC;
343 			break;
344 		}
345 		goto out;
346 	}
347 
348 	/* Did the call succeed? */
349 	if (reply->rp_status != 0) {
350 		/* Note: This is NOT an error code! */
351 		error = fxdr_unsigned(u_int32_t, reply->rp_status);
352 		switch (error) {
353 		    case RPC_PROGUNAVAIL:
354 			error = EPROGUNAVAIL;
355 			break;
356 		    case RPC_PROGMISMATCH:
357 			error = EPROGMISMATCH;
358 			break;
359 		    case RPC_PROCUNAVAIL:
360 			error = EPROCUNAVAIL;
361 			break;
362 		    case RPC_GARBAGE:
363 		    default:
364 			error = EBADRPC;
365 		}
366 		goto out;
367 	}
368 
369 	/*
370 	 * OK, we have received a good reply!
371 	 * Get its length, then strip it off.
372 	 */
373 	len = sizeof(*reply);
374 	if (reply->rp_auth.authtype != 0) {
375 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
376 		len = (len + 3) & ~3; /* XXX? */
377 	}
378 	m_adj(m, len);
379 
380 	/* result */
381 	*data = m;
382 	if (from_p) {
383 		*from_p = from;
384 		from = NULL;
385 	}
386 
387  out:
388 	if (nam) m_freem(nam);
389 	if (mhead) m_freem(mhead);
390 	if (from) m_freem(from);
391 	soclose(so);
392 	return error;
393 }
394 
395 /*
396  * eXternal Data Representation routines.
397  * (but with non-standard args...)
398  */
399 
400 /*
401  * String representation for RPC.
402  */
403 struct xdr_string {
404 	u_int32_t len;		/* length without null or padding */
405 	char data[4];	/* data (longer, of course) */
406     /* data is padded to a long-word boundary */
407 };
408 
409 struct mbuf *
410 xdr_string_encode(str, len)
411 	char *str;
412 	int len;
413 {
414 	struct mbuf *m;
415 	struct xdr_string *xs;
416 	int dlen;	/* padded string length */
417 	int mlen;	/* message length */
418 
419 	dlen = (len + 3) & ~3;
420 	mlen = dlen + 4;
421 
422 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
423 		return (NULL);
424 
425 	m = m_get(M_WAIT, MT_DATA);
426 	if (mlen > MLEN) {
427 		MCLGET(m, M_WAIT);
428 		if ((m->m_flags & M_EXT) == 0) {
429 			(void) m_free(m);	/* There can be only one. */
430 			return (NULL);
431 		}
432 	}
433 	xs = mtod(m, struct xdr_string *);
434 	m->m_len = mlen;
435 	xs->len = txdr_unsigned(len);
436 	memcpy(xs->data, str, len);
437 	return (m);
438 }
439 
440 struct mbuf *
441 xdr_string_decode(m, str, len_p)
442 	struct mbuf *m;
443 	char *str;
444 	int *len_p;		/* bufsize - 1 */
445 {
446 	struct xdr_string *xs;
447 	int mlen;	/* message length */
448 	int slen;	/* string length */
449 
450 	if (m->m_len < 4) {
451 		m = m_pullup(m, 4);
452 		if (m == NULL)
453 			return (NULL);
454 	}
455 	xs = mtod(m, struct xdr_string *);
456 	slen = fxdr_unsigned(u_int32_t, xs->len);
457 	mlen = 4 + ((slen + 3) & ~3);
458 
459 	if (slen > *len_p)
460 		slen = *len_p;
461 	m_copydata(m, 4, slen, str);
462 	m_adj(m, mlen);
463 
464 	str[slen] = '\0';
465 	*len_p = slen;
466 
467 	return (m);
468 }
469 
470 
471 /*
472  * Inet address in RPC messages
473  * (Note, really four ints, NOT chars.  Blech.)
474  */
475 struct xdr_inaddr {
476 	u_int32_t atype;
477 	u_int32_t addr[4];
478 };
479 
480 struct mbuf *
481 xdr_inaddr_encode(ia)
482 	struct in_addr *ia;		/* already in network order */
483 {
484 	struct mbuf *m;
485 	struct xdr_inaddr *xi;
486 	u_int8_t *cp;
487 	u_int32_t *ip;
488 
489 	m = m_get(M_WAIT, MT_DATA);
490 	xi = mtod(m, struct xdr_inaddr *);
491 	m->m_len = sizeof(*xi);
492 	xi->atype = txdr_unsigned(1);
493 	ip = xi->addr;
494 	cp = (u_int8_t *)&ia->s_addr;
495 	*ip++ = txdr_unsigned(*cp++);
496 	*ip++ = txdr_unsigned(*cp++);
497 	*ip++ = txdr_unsigned(*cp++);
498 	*ip++ = txdr_unsigned(*cp++);
499 
500 	return (m);
501 }
502 
503 struct mbuf *
504 xdr_inaddr_decode(m, ia)
505 	struct mbuf *m;
506 	struct in_addr *ia;		/* already in network order */
507 {
508 	struct xdr_inaddr *xi;
509 	u_int8_t *cp;
510 	u_int32_t *ip;
511 
512 	if (m->m_len < sizeof(*xi)) {
513 		m = m_pullup(m, sizeof(*xi));
514 		if (m == NULL)
515 			return (NULL);
516 	}
517 	xi = mtod(m, struct xdr_inaddr *);
518 	if (xi->atype != txdr_unsigned(1)) {
519 		ia->s_addr = INADDR_ANY;
520 		goto out;
521 	}
522 	ip = xi->addr;
523 	cp = (u_int8_t *)&ia->s_addr;
524 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
525 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
526 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
527 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
528 
529 out:
530 	m_adj(m, sizeof(*xi));
531 	return (m);
532 }
533