xref: /netbsd-src/sys/nfs/krpc_subr.c (revision c41a4eebefede43f6950f838a387dc18c6a431bf)
1 /*	$NetBSD: krpc_subr.c,v 1.21 1997/09/30 20:46:17 drochner 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/param.h>
46 #include <sys/systm.h>
47 #include <sys/conf.h>
48 #include <sys/ioctl.h>
49 #include <sys/proc.h>
50 #include <sys/mount.h>
51 #include <sys/mbuf.h>
52 #include <sys/reboot.h>
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 
56 #include <net/if.h>
57 #include <netinet/in.h>
58 
59 #include <nfs/rpcv2.h>
60 #include <nfs/krpc.h>
61 #include <nfs/xdr_subs.h>
62 #include <nfs/nfsproto.h> /* XXX NFSX_V3FHMAX for next */
63 #include <nfs/nfsdiskless.h> /* XXX decl nfs_boot_sendrecv */
64 
65 /*
66  * Kernel support for Sun RPC
67  *
68  * Used currently for bootstrapping in nfs diskless configurations.
69  */
70 
71 /*
72  * Generic RPC headers
73  */
74 
75 struct auth_info {
76 	u_int32_t 	authtype;	/* auth type */
77 	u_int32_t	authlen;	/* auth length */
78 };
79 
80 struct auth_unix {
81 	int32_t   ua_time;
82 	int32_t   ua_hostname;	/* null */
83 	int32_t   ua_uid;
84 	int32_t   ua_gid;
85 	int32_t   ua_gidlist;	/* null */
86 };
87 
88 struct rpc_call {
89 	u_int32_t	rp_xid;		/* request transaction id */
90 	int32_t 	rp_direction;	/* call direction (0) */
91 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
92 	u_int32_t	rp_prog;	/* program */
93 	u_int32_t	rp_vers;	/* version */
94 	u_int32_t	rp_proc;	/* procedure */
95 	struct	auth_info rpc_auth;
96 	struct	auth_unix rpc_unix;
97 	struct	auth_info rpc_verf;
98 };
99 
100 struct rpc_reply {
101 	u_int32_t rp_xid;		/* request transaction id */
102 	int32_t  rp_direction;		/* call direction (1) */
103 	int32_t  rp_astatus;		/* accept status (0: accepted) */
104 	union {
105 		/* rejected */
106 		struct {
107 			u_int32_t rej_stat;
108 			u_int32_t rej_val1;
109 			u_int32_t rej_val2;
110 		} rpu_rej;
111 		/* accepted */
112 		struct {
113 			struct auth_info rok_auth;
114 			u_int32_t	rok_status;
115 		} rpu_rok;
116 	} rp_u;
117 };
118 #define rp_rstat  rp_u.rpu_rej.rej_stat
119 #define rp_auth   rp_u.rpu_rok.rok_auth
120 #define rp_status rp_u.rpu_rok.rok_status
121 
122 #define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
123 
124 static int krpccheck __P((struct mbuf*, void*));
125 
126 /*
127  * Call portmap to lookup a port number for a particular rpc program
128  * Returns non-zero error on failure.
129  */
130 int
131 krpc_portmap(sin,  prog, vers, proto, portp)
132 	struct sockaddr_in *sin;		/* server address */
133 	u_int prog, vers, proto;	/* host order */
134 	u_int16_t *portp;	/* network order */
135 {
136 	struct sdata {
137 		u_int32_t prog;		/* call program */
138 		u_int32_t vers;		/* call version */
139 		u_int32_t proto;	/* call protocol */
140 		u_int32_t port;		/* call port (unused) */
141 	} *sdata;
142 	struct rdata {
143 		u_int16_t pad;
144 		u_int16_t port;
145 	} *rdata;
146 	struct mbuf *m;
147 	int error;
148 
149 	/* The portmapper port is fixed. */
150 	if (prog == PMAPPROG) {
151 		*portp = htons(PMAPPORT);
152 		return 0;
153 	}
154 
155 	m = m_get(M_WAIT, MT_DATA);
156 	sdata = mtod(m, struct sdata *);
157 	m->m_len = sizeof(*sdata);
158 
159 	/* Do the RPC to get it. */
160 	sdata->prog = txdr_unsigned(prog);
161 	sdata->vers = txdr_unsigned(vers);
162 	sdata->proto = txdr_unsigned(proto);
163 	sdata->port = 0;
164 
165 	sin->sin_port = htons(PMAPPORT);
166 	error = krpc_call(sin, PMAPPROG, PMAPVERS,
167 					  PMAPPROC_GETPORT, &m, NULL);
168 	if (error)
169 		return error;
170 
171 	if (m->m_len < sizeof(*rdata)) {
172 		m = m_pullup(m, sizeof(*rdata));
173 		if (m == NULL)
174 			return ENOBUFS;
175 	}
176 	rdata = mtod(m, struct rdata *);
177 	*portp = rdata->port;
178 
179 	m_freem(m);
180 	return 0;
181 }
182 
183 static int krpccheck(m, context)
184 struct mbuf *m;
185 void *context;
186 {
187 	struct rpc_reply *reply;
188 
189 	/* Does the reply contain at least a header? */
190 	if (m->m_pkthdr.len < MIN_REPLY_HDR)
191 		return(-1);
192 	if (m->m_len < sizeof(struct rpc_reply)) {
193 		m = m_pullup(m, sizeof(struct rpc_reply));
194 		if (m == NULL)
195 			return(-1);
196 	}
197 	reply = mtod(m, struct rpc_reply *);
198 
199 	/* Is it the right reply? */
200 	if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
201 		return(-1);
202 
203 	if (reply->rp_xid != txdr_unsigned(*(u_int32_t*)context))
204 		return(-1);
205 
206 	return(0);
207 }
208 
209 /*
210  * Do a remote procedure call (RPC) and wait for its reply.
211  * If from_p is non-null, then we are doing broadcast, and
212  * the address from whence the response came is saved there.
213  */
214 int
215 krpc_call(sa, prog, vers, func, data, from_p)
216 	struct sockaddr_in *sa;
217 	u_int prog, vers, func;
218 	struct mbuf **data;	/* input/output */
219 	struct mbuf **from_p;	/* output */
220 {
221 	struct socket *so;
222 	struct sockaddr_in *sin;
223 	struct mbuf *m, *nam, *mhead, *from;
224 	struct rpc_call *call;
225 	struct rpc_reply *reply;
226 	int error, len;
227 	static u_int32_t xid = ~0xFF;
228 	u_int16_t tport;
229 
230 	/*
231 	 * Validate address family.
232 	 * Sorry, this is INET specific...
233 	 */
234 	if (sa->sin_family != AF_INET)
235 		return (EAFNOSUPPORT);
236 
237 	/* Free at end if not null. */
238 	nam = mhead = NULL;
239 	from = NULL;
240 
241 	/*
242 	 * Create socket and set its recieve timeout.
243 	 */
244 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0)))
245 		goto out;
246 
247 	if ((error = nfs_boot_setrecvtimo(so)))
248 		goto out;
249 
250 	/*
251 	 * Enable broadcast if necessary.
252 	 */
253 	if (from_p) {
254 		if ((error = nfs_boot_enbroadcast(so)))
255 			goto out;
256 	}
257 
258 	/*
259 	 * Bind the local endpoint to a reserved port,
260 	 * because some NFS servers refuse requests from
261 	 * non-reserved (non-privileged) ports.
262 	 */
263 	tport = IPPORT_RESERVED;
264 	do {
265 		tport--;
266 		error = nfs_boot_sobind_ipport(so, tport);
267 	} while (error == EADDRINUSE &&
268 			 tport > IPPORT_RESERVED / 2);
269 	if (error) {
270 		printf("bind failed\n");
271 		goto out;
272 	}
273 
274 	/*
275 	 * Setup socket address for the server.
276 	 */
277 	nam = m_get(M_WAIT, MT_SONAME);
278 	sin = mtod(nam, struct sockaddr_in *);
279 	bcopy((caddr_t)sa, (caddr_t)sin,
280 		  (nam->m_len = sa->sin_len));
281 
282 	/*
283 	 * Prepend RPC message header.
284 	 */
285 	mhead = m_gethdr(M_WAIT, MT_DATA);
286 	mhead->m_next = *data;
287 	call = mtod(mhead, struct rpc_call *);
288 	mhead->m_len = sizeof(*call);
289 	bzero((caddr_t)call, sizeof(*call));
290 	/* rpc_call part */
291 	xid++;
292 	call->rp_xid = txdr_unsigned(xid);
293 	/* call->rp_direction = 0; */
294 	call->rp_rpcvers = txdr_unsigned(2);
295 	call->rp_prog = txdr_unsigned(prog);
296 	call->rp_vers = txdr_unsigned(vers);
297 	call->rp_proc = txdr_unsigned(func);
298 	/* rpc_auth part (auth_unix as root) */
299 	call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
300 	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
301 	/* rpc_verf part (auth_null) */
302 	call->rpc_verf.authtype = 0;
303 	call->rpc_verf.authlen  = 0;
304 
305 	/*
306 	 * Setup packet header
307 	 */
308 	len = 0;
309 	m = mhead;
310 	while (m) {
311 		len += m->m_len;
312 		m = m->m_next;
313 	}
314 	mhead->m_pkthdr.len = len;
315 	mhead->m_pkthdr.rcvif = NULL;
316 
317 	error = nfs_boot_sendrecv(so, nam, 0, mhead, krpccheck, &m, &from, &xid);
318 	if (error)
319 		goto out;
320 
321 	/* m_pullup() was done in krpccheck() */
322 	reply = mtod(m, struct rpc_reply *);
323 
324 	/* Was RPC accepted? (authorization OK) */
325 	if (reply->rp_astatus != 0) {
326 		/* Note: This is NOT an error code! */
327 		error = fxdr_unsigned(u_int32_t, reply->rp_rstat);
328 		switch (error) {
329 		    case RPC_MISMATCH:
330 			/* .re_status = RPC_VERSMISMATCH; */
331 			error = ERPCMISMATCH;
332 			break;
333 		    case RPC_AUTHERR:
334 			/* .re_status = RPC_AUTHERROR; */
335 			error = EAUTH;
336 			break;
337 		    default:
338 			/* unexpected */
339 			error = EBADRPC;
340 			break;
341 		}
342 		goto out;
343 	}
344 
345 	/* Did the call succeed? */
346 	if (reply->rp_status != 0) {
347 		/* Note: This is NOT an error code! */
348 		error = fxdr_unsigned(u_int32_t, reply->rp_status);
349 		switch (error) {
350 		    case RPC_PROGUNAVAIL:
351 			error = EPROGUNAVAIL;
352 			break;
353 		    case RPC_PROGMISMATCH:
354 			error = EPROGMISMATCH;
355 			break;
356 		    case RPC_PROCUNAVAIL:
357 			error = EPROCUNAVAIL;
358 			break;
359 		    case RPC_GARBAGE:
360 		    default:
361 			error = EBADRPC;
362 		}
363 		goto out;
364 	}
365 
366 	/*
367 	 * OK, we have received a good reply!
368 	 * Get its length, then strip it off.
369 	 */
370 	len = sizeof(*reply);
371 	if (reply->rp_auth.authtype != 0) {
372 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
373 		len = (len + 3) & ~3; /* XXX? */
374 	}
375 	m_adj(m, len);
376 
377 	/* result */
378 	*data = m;
379 	if (from_p) {
380 		*from_p = from;
381 		from = NULL;
382 	}
383 
384  out:
385 	if (nam) m_freem(nam);
386 	if (mhead) m_freem(mhead);
387 	if (from) m_freem(from);
388 	soclose(so);
389 	return error;
390 }
391 
392 /*
393  * eXternal Data Representation routines.
394  * (but with non-standard args...)
395  */
396 
397 /*
398  * String representation for RPC.
399  */
400 struct xdr_string {
401 	u_int32_t len;		/* length without null or padding */
402 	char data[4];	/* data (longer, of course) */
403     /* data is padded to a long-word boundary */
404 };
405 
406 struct mbuf *
407 xdr_string_encode(str, len)
408 	char *str;
409 	int len;
410 {
411 	struct mbuf *m;
412 	struct xdr_string *xs;
413 	int dlen;	/* padded string length */
414 	int mlen;	/* message length */
415 
416 	dlen = (len + 3) & ~3;
417 	mlen = dlen + 4;
418 
419 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
420 		return (NULL);
421 
422 	m = m_get(M_WAIT, MT_DATA);
423 	if (mlen > MLEN) {
424 		MCLGET(m, M_WAIT);
425 		if ((m->m_flags & M_EXT) == 0) {
426 			(void) m_free(m);	/* There can be only one. */
427 			return (NULL);
428 		}
429 	}
430 	xs = mtod(m, struct xdr_string *);
431 	m->m_len = mlen;
432 	xs->len = txdr_unsigned(len);
433 	bcopy(str, xs->data, len);
434 	return (m);
435 }
436 
437 struct mbuf *
438 xdr_string_decode(m, str, len_p)
439 	struct mbuf *m;
440 	char *str;
441 	int *len_p;		/* bufsize - 1 */
442 {
443 	struct xdr_string *xs;
444 	int mlen;	/* message length */
445 	int slen;	/* string length */
446 
447 	if (m->m_len < 4) {
448 		m = m_pullup(m, 4);
449 		if (m == NULL)
450 			return (NULL);
451 	}
452 	xs = mtod(m, struct xdr_string *);
453 	slen = fxdr_unsigned(u_int32_t, xs->len);
454 	mlen = 4 + ((slen + 3) & ~3);
455 
456 	if (slen > *len_p)
457 		slen = *len_p;
458 	m_copydata(m, 4, slen, str);
459 	m_adj(m, mlen);
460 
461 	str[slen] = '\0';
462 	*len_p = slen;
463 
464 	return (m);
465 }
466 
467 
468 /*
469  * Inet address in RPC messages
470  * (Note, really four ints, NOT chars.  Blech.)
471  */
472 struct xdr_inaddr {
473 	u_int32_t atype;
474 	u_int32_t addr[4];
475 };
476 
477 struct mbuf *
478 xdr_inaddr_encode(ia)
479 	struct in_addr *ia;		/* already in network order */
480 {
481 	struct mbuf *m;
482 	struct xdr_inaddr *xi;
483 	u_int8_t *cp;
484 	u_int32_t *ip;
485 
486 	m = m_get(M_WAIT, MT_DATA);
487 	xi = mtod(m, struct xdr_inaddr *);
488 	m->m_len = sizeof(*xi);
489 	xi->atype = txdr_unsigned(1);
490 	ip = xi->addr;
491 	cp = (u_int8_t *)&ia->s_addr;
492 	*ip++ = txdr_unsigned(*cp++);
493 	*ip++ = txdr_unsigned(*cp++);
494 	*ip++ = txdr_unsigned(*cp++);
495 	*ip++ = txdr_unsigned(*cp++);
496 
497 	return (m);
498 }
499 
500 struct mbuf *
501 xdr_inaddr_decode(m, ia)
502 	struct mbuf *m;
503 	struct in_addr *ia;		/* already in network order */
504 {
505 	struct xdr_inaddr *xi;
506 	u_int8_t *cp;
507 	u_int32_t *ip;
508 
509 	if (m->m_len < sizeof(*xi)) {
510 		m = m_pullup(m, sizeof(*xi));
511 		if (m == NULL)
512 			return (NULL);
513 	}
514 	xi = mtod(m, struct xdr_inaddr *);
515 	if (xi->atype != txdr_unsigned(1)) {
516 		ia->s_addr = INADDR_ANY;
517 		goto out;
518 	}
519 	ip = xi->addr;
520 	cp = (u_int8_t *)&ia->s_addr;
521 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
522 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
523 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
524 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
525 
526 out:
527 	m_adj(m, sizeof(*xi));
528 	return (m);
529 }
530