xref: /netbsd-src/sys/nfs/krpc_subr.c (revision f89f6560d453f5e37386cc7938c072d2f528b9fa)
1 /*	$NetBSD: krpc_subr.c,v 1.39 2015/03/27 07:18:11 hikaru 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 1.39 2015/03/27 07:18:11 hikaru 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, *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 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 	nam = m_get(M_WAIT, MT_SONAME);
278 	sin = mtod(nam, struct sockaddr_in *);
279 	memcpy((void *)sin, (void *)sa,
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 	memset((void *)call, 0, 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,
318 	    &xid, l);
319 	if (error)
320 		goto out;
321 
322 	/* m_pullup() was done in krpccheck() */
323 	reply = mtod(m, struct rpc_reply *);
324 
325 	/* Was RPC accepted? (authorization OK) */
326 	if (reply->rp_astatus != 0) {
327 		/* Note: This is NOT an error code! */
328 		error = fxdr_unsigned(u_int32_t, reply->rp_rstat);
329 		switch (error) {
330 		    case RPC_MISMATCH:
331 			/* .re_status = RPC_VERSMISMATCH; */
332 			error = ERPCMISMATCH;
333 			break;
334 		    case RPC_AUTHERR:
335 			/* .re_status = RPC_AUTHERROR; */
336 			error = EAUTH;
337 			break;
338 		    default:
339 			/* unexpected */
340 			error = EBADRPC;
341 			break;
342 		}
343 		goto out;
344 	}
345 
346 	/* Did the call succeed? */
347 	if (reply->rp_status != 0) {
348 		/* Note: This is NOT an error code! */
349 		error = fxdr_unsigned(u_int32_t, reply->rp_status);
350 		switch (error) {
351 		    case RPC_PROGUNAVAIL:
352 			error = EPROGUNAVAIL;
353 			break;
354 		    case RPC_PROGMISMATCH:
355 			error = EPROGMISMATCH;
356 			break;
357 		    case RPC_PROCUNAVAIL:
358 			error = EPROCUNAVAIL;
359 			break;
360 		    case RPC_GARBAGE:
361 		    default:
362 			error = EBADRPC;
363 		}
364 		goto out;
365 	}
366 
367 	/*
368 	 * OK, we have received a good reply!
369 	 * Get its length, then strip it off.
370 	 */
371 	len = sizeof(*reply);
372 	if (reply->rp_auth.authtype != 0) {
373 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
374 		len = (len + 3) & ~3; /* XXX? */
375 	}
376 	m_adj(m, len);
377 
378 	/* result */
379 	*data = m;
380 	if (from_p && error == 0) {
381 		*from_p = from;
382 		from = NULL;
383 	}
384 
385  out:
386 	if (nam) m_freem(nam);
387 	if (mhead) m_freem(mhead);
388 	if (from) m_freem(from);
389 	soclose(so);
390 	return error;
391 }
392 
393 /*
394  * eXternal Data Representation routines.
395  * (but with non-standard args...)
396  */
397 
398 /*
399  * String representation for RPC.
400  */
401 struct xdr_string {
402 	u_int32_t len;		/* length without null or padding */
403 	char data[4];	/* data (longer, of course) */
404     /* data is padded to a long-word boundary */
405 };
406 
407 struct mbuf *
408 xdr_string_encode(char *str, int len)
409 {
410 	struct mbuf *m;
411 	struct xdr_string *xs;
412 	int dlen;	/* padded string length */
413 	int mlen;	/* message length */
414 
415 	dlen = (len + 3) & ~3;
416 	mlen = dlen + 4;
417 
418 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
419 		return (NULL);
420 
421 	m = m_get(M_WAIT, MT_DATA);
422 	if (mlen > MLEN) {
423 		m_clget(m, M_WAIT);
424 		if ((m->m_flags & M_EXT) == 0) {
425 			(void) m_free(m);	/* There can be only one. */
426 			return (NULL);
427 		}
428 	}
429 	xs = mtod(m, struct xdr_string *);
430 	m->m_len = mlen;
431 	xs->len = txdr_unsigned(len);
432 	memcpy(xs->data, str, len);
433 	return (m);
434 }
435 
436 struct mbuf *
437 xdr_string_decode(struct mbuf *m, char *str, int *len_p)
438 	/* len_p:		 bufsize - 1 */
439 {
440 	struct xdr_string *xs;
441 	int mlen;	/* message length */
442 	int slen;	/* string length */
443 
444 	if (m->m_len < 4) {
445 		m = m_pullup(m, 4);
446 		if (m == NULL)
447 			return (NULL);
448 	}
449 	xs = mtod(m, struct xdr_string *);
450 	slen = fxdr_unsigned(u_int32_t, xs->len);
451 	mlen = 4 + ((slen + 3) & ~3);
452 
453 	if (slen > *len_p)
454 		slen = *len_p;
455 	m_copydata(m, 4, slen, str);
456 	m_adj(m, mlen);
457 
458 	str[slen] = '\0';
459 	*len_p = slen;
460 
461 	return (m);
462 }
463 
464 
465 /*
466  * Inet address in RPC messages
467  * (Note, really four ints, NOT chars.  Blech.)
468  */
469 struct xdr_inaddr {
470 	u_int32_t atype;
471 	u_int32_t addr[4];
472 };
473 
474 struct mbuf *
475 xdr_inaddr_encode(struct in_addr *ia)
476 	/* ia:		 already in network order */
477 {
478 	struct mbuf *m;
479 	struct xdr_inaddr *xi;
480 	u_int8_t *cp;
481 	u_int32_t *ip;
482 
483 	m = m_get(M_WAIT, MT_DATA);
484 	xi = mtod(m, struct xdr_inaddr *);
485 	m->m_len = sizeof(*xi);
486 	xi->atype = txdr_unsigned(1);
487 	ip = xi->addr;
488 	cp = (u_int8_t *)&ia->s_addr;
489 	*ip++ = txdr_unsigned(*cp++);
490 	*ip++ = txdr_unsigned(*cp++);
491 	*ip++ = txdr_unsigned(*cp++);
492 	*ip++ = txdr_unsigned(*cp++);
493 
494 	return (m);
495 }
496 
497 struct mbuf *
498 xdr_inaddr_decode(struct mbuf *m, struct in_addr *ia)
499 	/* ia:		 already in network order */
500 {
501 	struct xdr_inaddr *xi;
502 	u_int8_t *cp;
503 	u_int32_t *ip;
504 
505 	if (m->m_len < sizeof(*xi)) {
506 		m = m_pullup(m, sizeof(*xi));
507 		if (m == NULL)
508 			return (NULL);
509 	}
510 	xi = mtod(m, struct xdr_inaddr *);
511 	if (xi->atype != txdr_unsigned(1)) {
512 		ia->s_addr = INADDR_ANY;
513 		goto out;
514 	}
515 	ip = xi->addr;
516 	cp = (u_int8_t *)&ia->s_addr;
517 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
518 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
519 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
520 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
521 
522 out:
523 	m_adj(m, sizeof(*xi));
524 	return (m);
525 }
526