xref: /netbsd-src/sys/nfs/krpc_subr.c (revision c94bf7cb489840bf1d8df08d9cb6179007cc7fe2)
1 /*	$NetBSD: krpc_subr.c,v 1.44 2024/10/20 14:01:52 mlelstv 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 1.44 2024/10/20 14:01:52 mlelstv 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(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(struct sockaddr_in *sin, u_int prog, u_int vers, u_int proto, u_int16_t *portp, struct lwp *l)
135 	/* sin:		 server address */
136 	/* prog, vers, proto:	 host order */
137 	/* 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, l);
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(struct mbuf **mp, void *context)
187 {
188 	struct rpc_reply *reply;
189 	struct mbuf *m = *mp;
190 
191 	/* Does the reply contain at least a header? */
192 	if (m->m_pkthdr.len < MIN_REPLY_HDR)
193 		return(-1);
194 	if (m->m_len < sizeof(struct rpc_reply)) {
195 		m = *mp = m_pullup(m, sizeof(struct rpc_reply));
196 		if (m == NULL)
197 			return(-1);
198 	}
199 	reply = mtod(m, struct rpc_reply *);
200 
201 	/* Is it the right reply? */
202 	if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
203 		return(-1);
204 
205 	if (reply->rp_xid != txdr_unsigned(*(u_int32_t*)context))
206 		return(-1);
207 
208 	return(0);
209 }
210 
211 /*
212  * Do a remote procedure call (RPC) and wait for its reply.
213  * If from_p is non-null, then we are doing broadcast, and
214  * the address from whence the response came is saved there.
215  */
216 int
217 krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func, struct mbuf **data, struct mbuf **from_p, struct lwp *l)
218 	/* data:	 input/output */
219 	/* from_p:	 output */
220 {
221 	struct socket *so;
222 	struct sockaddr_in sin;
223 	struct mbuf *m, *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 	mhead = NULL;
239 	from = NULL;
240 
241 	/*
242 	 * Create socket and set its receive timeout.
243 	 */
244 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, l, NULL)))
245 		return error;
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, l);
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 	sin = *sa;
278 
279 	/*
280 	 * Prepend RPC message header.
281 	 */
282 	mhead = m_gethdr(M_WAIT, MT_DATA);
283 	MCLAIM(mhead, &nfs_mowner);
284 	mhead->m_next = *data;
285 	call = mtod(mhead, struct rpc_call *);
286 	mhead->m_len = sizeof(*call);
287 	memset((void *)call, 0, sizeof(*call));
288 	/* rpc_call part */
289 	xid++;
290 	call->rp_xid = txdr_unsigned(xid);
291 	/* call->rp_direction = 0; */
292 	call->rp_rpcvers = txdr_unsigned(2);
293 	call->rp_prog = txdr_unsigned(prog);
294 	call->rp_vers = txdr_unsigned(vers);
295 	call->rp_proc = txdr_unsigned(func);
296 	/* rpc_auth part (auth_unix as root) */
297 	call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
298 	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
299 	/* rpc_verf part (auth_null) */
300 	call->rpc_verf.authtype = 0;
301 	call->rpc_verf.authlen  = 0;
302 
303 	/*
304 	 * Setup packet header
305 	 */
306 	len = 0;
307 	m = mhead;
308 	while (m) {
309 		len += m->m_len;
310 		m = m->m_next;
311 	}
312 	mhead->m_pkthdr.len = len;
313 	m_reset_rcvif(mhead);
314 
315 	error = nfs_boot_sendrecv(so, &sin, NULL, mhead, krpccheck, &m, &from,
316 	    &xid, l);
317 	if (error)
318 		goto out;
319 
320 	/* m_pullup() was done in krpccheck() */
321 	reply = mtod(m, struct rpc_reply *);
322 
323 	/* Was RPC accepted? (authorization OK) */
324 	if (reply->rp_astatus != 0) {
325 		/* Note: This is NOT an error code! */
326 		error = fxdr_unsigned(u_int32_t, reply->rp_rstat);
327 		switch (error) {
328 		    case RPC_MISMATCH:
329 			/* .re_status = RPC_VERSMISMATCH; */
330 			error = ERPCMISMATCH;
331 			break;
332 		    case RPC_AUTHERR:
333 			/* .re_status = RPC_AUTHERROR; */
334 			error = EAUTH;
335 			break;
336 		    default:
337 			/* unexpected */
338 			error = EBADRPC;
339 			break;
340 		}
341 		goto out;
342 	}
343 
344 	/* Did the call succeed? */
345 	if (reply->rp_status != 0) {
346 		/* Note: This is NOT an error code! */
347 		error = fxdr_unsigned(u_int32_t, reply->rp_status);
348 		switch (error) {
349 		    case RPC_PROGUNAVAIL:
350 			error = EPROGUNAVAIL;
351 			break;
352 		    case RPC_PROGMISMATCH:
353 			error = EPROGMISMATCH;
354 			break;
355 		    case RPC_PROCUNAVAIL:
356 			error = EPROCUNAVAIL;
357 			break;
358 		    case RPC_GARBAGE:
359 		    default:
360 			error = EBADRPC;
361 		}
362 		goto out;
363 	}
364 
365 	/*
366 	 * OK, we have received a good reply!
367 	 * Get its length, then strip it off.
368 	 */
369 	len = sizeof(*reply);
370 	if (reply->rp_auth.authtype != 0) {
371 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
372 		len = (len + 3) & ~3; /* XXX? */
373 	}
374 	m_adj(m, len);
375 
376 	/* result */
377 	*data = m;
378 	if (from_p && error == 0) {
379 		*from_p = from;
380 		from = NULL;
381 	}
382 
383  out:
384 	m_freem(mhead);
385 	m_freem(from);
386 	soclose(so);
387 	return error;
388 }
389 
390 /*
391  * eXternal Data Representation routines.
392  * (but with non-standard args...)
393  */
394 
395 /*
396  * String representation for RPC.
397  */
398 struct xdr_string {
399 	u_int32_t len;		/* length without null or padding */
400 	char data[4];	/* data (longer, of course) */
401     /* data is padded to a long-word boundary */
402 };
403 
404 struct mbuf *
405 xdr_string_encode(char *str, int len)
406 {
407 	struct mbuf *m;
408 	struct xdr_string *xs;
409 	int dlen;	/* padded string length */
410 	int mlen;	/* message length */
411 
412 	dlen = (len + 3) & ~3;
413 	mlen = dlen + 4;
414 
415 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
416 		return (NULL);
417 
418 	m = m_get(M_WAIT, MT_DATA);
419 	if (mlen > MLEN) {
420 		m_clget(m, M_WAIT);
421 		if ((m->m_flags & M_EXT) == 0) {
422 			(void) m_free(m);	/* There can be only one. */
423 			return (NULL);
424 		}
425 	}
426 	xs = mtod(m, struct xdr_string *);
427 	m->m_len = mlen;
428 	xs->len = txdr_unsigned(len);
429 	memcpy(xs->data, str, len);
430 	return (m);
431 }
432 
433 struct mbuf *
434 xdr_string_decode(struct mbuf *m, char *str, int *len_p)
435 	/* len_p:		 bufsize - 1 */
436 {
437 	struct xdr_string *xs;
438 	int mlen;	/* message length */
439 	int slen;	/* string length */
440 
441 	if (m->m_len < 4) {
442 		m = m_pullup(m, 4);
443 		if (m == NULL)
444 			return (NULL);
445 	}
446 	xs = mtod(m, struct xdr_string *);
447 	slen = fxdr_unsigned(u_int32_t, xs->len);
448 	mlen = 4 + ((slen + 3) & ~3);
449 
450 	if (slen > *len_p)
451 		slen = *len_p;
452 	m_copydata(m, 4, slen, str);
453 	m_adj(m, mlen);
454 
455 	str[slen] = '\0';
456 	*len_p = slen;
457 
458 	return (m);
459 }
460 
461 
462 /*
463  * Inet address in RPC messages
464  * (Note, really four ints, NOT chars.  Blech.)
465  */
466 struct xdr_inaddr {
467 	u_int32_t atype;
468 	u_int32_t addr[4];
469 };
470 
471 struct mbuf *
472 xdr_inaddr_encode(struct in_addr *ia)
473 	/* ia:		 already in network order */
474 {
475 	struct mbuf *m;
476 	struct xdr_inaddr *xi;
477 	u_int8_t *cp;
478 	u_int32_t *ip;
479 
480 	m = m_get(M_WAIT, MT_DATA);
481 	xi = mtod(m, struct xdr_inaddr *);
482 	m->m_len = sizeof(*xi);
483 	xi->atype = txdr_unsigned(1);
484 	ip = xi->addr;
485 	cp = (u_int8_t *)&ia->s_addr;
486 	*ip++ = txdr_unsigned(*cp++);
487 	*ip++ = txdr_unsigned(*cp++);
488 	*ip++ = txdr_unsigned(*cp++);
489 	*ip++ = txdr_unsigned(*cp++);
490 
491 	return (m);
492 }
493 
494 struct mbuf *
495 xdr_inaddr_decode(struct mbuf *m, struct in_addr *ia)
496 	/* ia:		 already in network order */
497 {
498 	struct xdr_inaddr *xi;
499 	u_int8_t *cp;
500 	u_int32_t *ip;
501 
502 	if (m->m_len < sizeof(*xi)) {
503 		m = m_pullup(m, sizeof(*xi));
504 		if (m == NULL)
505 			return (NULL);
506 	}
507 	xi = mtod(m, struct xdr_inaddr *);
508 	if (xi->atype != txdr_unsigned(1)) {
509 		ia->s_addr = INADDR_ANY;
510 		goto out;
511 	}
512 	ip = xi->addr;
513 	cp = (u_int8_t *)&ia->s_addr;
514 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
515 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
516 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
517 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
518 
519 out:
520 	m_adj(m, sizeof(*xi));
521 	return (m);
522 }
523