xref: /dragonfly/sys/vfs/nfs/krpc_subr.c (revision 2cd2d2b5) 
1 /*	$NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd Exp $	*/
2 /* $FreeBSD: src/sys/nfs/krpc_subr.c,v 1.13.2.1 2000/11/20 21:17:14 tegge Exp $	*/
3 /* $DragonFly: src/sys/vfs/nfs/krpc_subr.c,v 1.6 2004/06/02 14:43:04 eirikn Exp $	*/
4 
5 /*
6  * Copyright (c) 1995 Gordon Ross, Adam Glass
7  * Copyright (c) 1992 Regents of the University of California.
8  * All rights reserved.
9  *
10  * This software was developed by the Computer Systems Engineering group
11  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
12  * contributed to Berkeley.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. All advertising materials mentioning features or use of this software
23  *    must display the following acknowledgement:
24  *	This product includes software developed by the University of
25  *	California, Lawrence Berkeley Laboratory and its contributors.
26  * 4. Neither the name of the University nor the names of its contributors
27  *    may be used to endorse or promote products derived from this software
28  *    without specific prior written permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40  * SUCH DAMAGE.
41  *
42  * partially based on:
43  *      libnetboot/rpc.c
44  *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
45  */
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/malloc.h>
50 #include <sys/mbuf.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53 #include <sys/uio.h>
54 
55 #include <net/if.h>
56 #include <netinet/in.h>
57 
58 #include "rpcv2.h"
59 #include "krpc.h"
60 #include "xdr_subs.h"
61 
62 /*
63  * Kernel support for Sun RPC
64  *
65  * Used currently for bootstrapping in nfs diskless configurations.
66  */
67 
68 /*
69  * Generic RPC headers
70  */
71 
72 struct auth_info {
73 	u_int32_t 	authtype;	/* auth type */
74 	u_int32_t	authlen;	/* auth length */
75 };
76 
77 struct auth_unix {
78 	int32_t   ua_time;
79 	int32_t   ua_hostname;	/* null */
80 	int32_t   ua_uid;
81 	int32_t   ua_gid;
82 	int32_t   ua_gidlist;	/* null */
83 };
84 
85 struct rpc_call {
86 	u_int32_t	rp_xid;		/* request transaction id */
87 	int32_t 	rp_direction;	/* call direction (0) */
88 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
89 	u_int32_t	rp_prog;	/* program */
90 	u_int32_t	rp_vers;	/* version */
91 	u_int32_t	rp_proc;	/* procedure */
92 	struct	auth_info rpc_auth;
93 	struct	auth_unix rpc_unix;
94 	struct	auth_info rpc_verf;
95 };
96 
97 struct rpc_reply {
98 	u_int32_t rp_xid;		/* request transaction id */
99 	int32_t  rp_direction;		/* call direction (1) */
100 	int32_t  rp_astatus;		/* accept status (0: accepted) */
101 	union {
102 		u_int32_t rpu_errno;
103 		struct {
104 			struct auth_info rok_auth;
105 			u_int32_t	rok_status;
106 		} rpu_rok;
107 	} rp_u;
108 };
109 #define rp_errno  rp_u.rpu_errno
110 #define rp_auth   rp_u.rpu_rok.rok_auth
111 #define rp_status rp_u.rpu_rok.rok_status
112 
113 #define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
114 
115 /*
116  * What is the longest we will wait before re-sending a request?
117  * Note this is also the frequency of "RPC timeout" messages.
118  * The re-send loop count sup linearly to this maximum, so the
119  * first complaint will happen after (1+2+3+4+5)=15 seconds.
120  */
121 #define	MAX_RESEND_DELAY 5	/* seconds */
122 
123 /*
124  * Call portmap to lookup a port number for a particular rpc program
125  * Returns non-zero error on failure.
126  */
127 int
128 krpc_portmap(struct sockaddr_in *sin,	/* server address */
129 	     u_int prog, u_int vers,	/* host order */
130 	     u_int16_t *portp,		/* network order */
131 	     struct thread *td)
132 {
133 	struct sdata {
134 		u_int32_t prog;		/* call program */
135 		u_int32_t vers;		/* call version */
136 		u_int32_t proto;	/* call protocol */
137 		u_int32_t port;		/* call port (unused) */
138 	} *sdata;
139 	struct rdata {
140 		u_int16_t pad;
141 		u_int16_t port;
142 	} *rdata;
143 	struct mbuf *m;
144 	int error;
145 
146 	/* The portmapper port is fixed. */
147 	if (prog == PMAPPROG) {
148 		*portp = htons(PMAPPORT);
149 		return 0;
150 	}
151 
152 	m = m_get(MB_WAIT, MT_DATA);
153 	if (m == NULL)
154 		return ENOBUFS;
155 	sdata = mtod(m, struct sdata *);
156 	m->m_len = sizeof(*sdata);
157 
158 	/* Do the RPC to get it. */
159 	sdata->prog = txdr_unsigned(prog);
160 	sdata->vers = txdr_unsigned(vers);
161 	sdata->proto = txdr_unsigned(IPPROTO_UDP);
162 	sdata->port = 0;
163 
164 	sin->sin_port = htons(PMAPPORT);
165 	error = krpc_call(sin, PMAPPROG, PMAPVERS,
166 					  PMAPPROC_GETPORT, &m, NULL, td);
167 	if (error)
168 		return error;
169 
170 	if (m->m_len < sizeof(*rdata)) {
171 		m = m_pullup(m, sizeof(*rdata));
172 		if (m == NULL)
173 			return ENOBUFS;
174 	}
175 	rdata = mtod(m, struct rdata *);
176 	*portp = rdata->port;
177 
178 	m_freem(m);
179 	return 0;
180 }
181 
182 /*
183  * Do a remote procedure call (RPC) and wait for its reply.
184  * If from_p is non-null, then we are doing broadcast, and
185  * the address from whence the response came is saved there.
186  */
187 int
188 krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
189 	  struct mbuf **data,		/* input/output */
190 	  struct sockaddr **from_p,	/* output */
191 	  struct thread *td)
192 {
193 	struct socket *so;
194 	struct sockaddr_in *sin, ssin;
195 	struct sockaddr *from;
196 	struct mbuf *m, *nam, *mhead;
197 	struct rpc_call *call;
198 	struct rpc_reply *reply;
199 	struct sockopt sopt;
200 	struct timeval tv;
201 	struct uio auio;
202 	int error, rcvflg, timo, secs, len;
203 	static u_int32_t xid = ~0xFF;
204 	u_int16_t tport;
205 	u_int32_t saddr;
206 
207 	/*
208 	 * Validate address family.
209 	 * Sorry, this is INET specific...
210 	 */
211 	if (sa->sin_family != AF_INET)
212 		return (EAFNOSUPPORT);
213 
214 	/* Free at end if not null. */
215 	nam = mhead = NULL;
216 	from = NULL;
217 
218 	/*
219 	 * Create socket and set its recieve timeout.
220 	 */
221 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td)))
222 		goto out;
223 
224 	tv.tv_sec = 1;
225 	tv.tv_usec = 0;
226 	bzero(&sopt, sizeof sopt);
227 	sopt.sopt_level = SOL_SOCKET;
228 	sopt.sopt_name = SO_RCVTIMEO;
229 	sopt.sopt_val = &tv;
230 	sopt.sopt_valsize = sizeof tv;
231 
232 	if ((error = sosetopt(so, &sopt)) != 0)
233 		goto out;
234 
235 	/*
236 	 * Enable broadcast if necessary.
237 	 */
238 	if (from_p) {
239 		int on = 1;
240 		sopt.sopt_name = SO_BROADCAST;
241 		sopt.sopt_val = &on;
242 		sopt.sopt_valsize = sizeof on;
243 		if ((error = sosetopt(so, &sopt)) != 0)
244 			goto out;
245 	}
246 
247 	/*
248 	 * Bind the local endpoint to a reserved port,
249 	 * because some NFS servers refuse requests from
250 	 * non-reserved (non-privileged) ports.
251 	 */
252 	sin = &ssin;
253 	bzero(sin, sizeof *sin);
254 	sin->sin_len = sizeof(*sin);
255 	sin->sin_family = AF_INET;
256 	sin->sin_addr.s_addr = INADDR_ANY;
257 	tport = IPPORT_RESERVED;
258 	do {
259 		tport--;
260 		sin->sin_port = htons(tport);
261 		error = sobind(so, (struct sockaddr *)sin, td);
262 	} while (error == EADDRINUSE &&
263 			 tport > IPPORT_RESERVED / 2);
264 	if (error) {
265 		printf("bind failed\n");
266 		goto out;
267 	}
268 
269 	/*
270 	 * Setup socket address for the server.
271 	 */
272 
273 	/*
274 	 * Prepend RPC message header.
275 	 */
276 	mhead = m_gethdr(MB_WAIT, MT_DATA);
277 	mhead->m_next = *data;
278 	call = mtod(mhead, struct rpc_call *);
279 	mhead->m_len = sizeof(*call);
280 	bzero((caddr_t)call, sizeof(*call));
281 	/* rpc_call part */
282 	xid++;
283 	call->rp_xid = txdr_unsigned(xid);
284 	/* call->rp_direction = 0; */
285 	call->rp_rpcvers = txdr_unsigned(2);
286 	call->rp_prog = txdr_unsigned(prog);
287 	call->rp_vers = txdr_unsigned(vers);
288 	call->rp_proc = txdr_unsigned(func);
289 	/* rpc_auth part (auth_unix as root) */
290 	call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
291 	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
292 	/* rpc_verf part (auth_null) */
293 	call->rpc_verf.authtype = 0;
294 	call->rpc_verf.authlen  = 0;
295 
296 	/*
297 	 * Setup packet header
298 	 */
299 	len = 0;
300 	m = mhead;
301 	while (m) {
302 		len += m->m_len;
303 		m = m->m_next;
304 	}
305 	mhead->m_pkthdr.len = len;
306 	mhead->m_pkthdr.rcvif = NULL;
307 
308 	/*
309 	 * Send it, repeatedly, until a reply is received,
310 	 * but delay each re-send by an increasing amount.
311 	 * If the delay hits the maximum, start complaining.
312 	 */
313 	timo = 0;
314 	for (;;) {
315 		/* Send RPC request (or re-send). */
316 		m = m_copym(mhead, 0, M_COPYALL, MB_WAIT);
317 		if (m == NULL) {
318 			error = ENOBUFS;
319 			goto out;
320 		}
321 		error = sosend(so, (struct sockaddr *)sa, NULL, m,
322 			       NULL, 0, td);
323 		if (error) {
324 			printf("krpc_call: sosend: %d\n", error);
325 			goto out;
326 		}
327 		m = NULL;
328 
329 		/* Determine new timeout. */
330 		if (timo < MAX_RESEND_DELAY)
331 			timo++;
332 		else {
333 			saddr = ntohl(sa->sin_addr.s_addr);
334 			printf("RPC timeout for server %d.%d.%d.%d\n",
335 			       (saddr >> 24) & 255,
336 			       (saddr >> 16) & 255,
337 			       (saddr >> 8) & 255,
338 			       saddr & 255);
339 		}
340 
341 		/*
342 		 * Wait for up to timo seconds for a reply.
343 		 * The socket receive timeout was set to 1 second.
344 		 */
345 		secs = timo;
346 		while (secs > 0) {
347 			if (from) {
348 				FREE(from, M_SONAME);
349 				from = NULL;
350 			}
351 			if (m) {
352 				m_freem(m);
353 				m = NULL;
354 			}
355 			bzero(&auio,sizeof(auio));
356 			auio.uio_resid = len = 1<<16;
357 			rcvflg = 0;
358 			error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
359 			if (error == EWOULDBLOCK) {
360 				secs--;
361 				continue;
362 			}
363 			if (error)
364 				goto out;
365 			len -= auio.uio_resid;
366 
367 			/* Does the reply contain at least a header? */
368 			if (len < MIN_REPLY_HDR)
369 				continue;
370 			if (m->m_len < MIN_REPLY_HDR)
371 				continue;
372 			reply = mtod(m, struct rpc_reply *);
373 
374 			/* Is it the right reply? */
375 			if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
376 				continue;
377 
378 			if (reply->rp_xid != txdr_unsigned(xid))
379 				continue;
380 
381 			/* Was RPC accepted? (authorization OK) */
382 			if (reply->rp_astatus != 0) {
383 				error = fxdr_unsigned(u_int32_t, reply->rp_errno);
384 				printf("rpc denied, error=%d\n", error);
385 				continue;
386 			}
387 
388 			/* Did the call succeed? */
389 			if (reply->rp_status != 0) {
390 				error = fxdr_unsigned(u_int32_t, reply->rp_status);
391 				if (error == RPC_PROGMISMATCH) {
392 				  error = EBADRPC;
393 				  goto out;
394 				}
395 				printf("rpc denied, status=%d\n", error);
396 				continue;
397 			}
398 
399 			goto gotreply;	/* break two levels */
400 
401 		} /* while secs */
402 	} /* forever send/receive */
403 
404 	error = ETIMEDOUT;
405 	goto out;
406 
407  gotreply:
408 
409 	/*
410 	 * Get RPC reply header into first mbuf,
411 	 * get its length, then strip it off.
412 	 */
413 	len = sizeof(*reply);
414 	if (m->m_len < len) {
415 		m = m_pullup(m, len);
416 		if (m == NULL) {
417 			error = ENOBUFS;
418 			goto out;
419 		}
420 	}
421 	reply = mtod(m, struct rpc_reply *);
422 	if (reply->rp_auth.authtype != 0) {
423 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
424 		len = (len + 3) & ~3; /* XXX? */
425 	}
426 	m_adj(m, len);
427 
428 	/* result */
429 	*data = m;
430 	if (from_p) {
431 		*from_p = from;
432 		from = NULL;
433 	}
434 
435  out:
436 	if (mhead) m_freem(mhead);
437 	if (from) free(from, M_SONAME);
438 	soclose(so);
439 	return error;
440 }
441 
442 /*
443  * eXternal Data Representation routines.
444  * (but with non-standard args...)
445  */
446 
447 /*
448  * String representation for RPC.
449  */
450 struct xdr_string {
451 	u_int32_t len;		/* length without null or padding */
452 	char data[4];	/* data (longer, of course) */
453     /* data is padded to a long-word boundary */
454 };
455 
456 struct mbuf *
457 xdr_string_encode(char *str, int len)
458 {
459 	struct mbuf *m;
460 	struct xdr_string *xs;
461 	int dlen;	/* padded string length */
462 	int mlen;	/* message length */
463 
464 	dlen = (len + 3) & ~3;
465 	mlen = dlen + 4;
466 
467 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
468 		return (NULL);
469 
470 	m = m_get(MB_WAIT, MT_DATA);
471 	if (mlen > MLEN) {
472 		MCLGET(m, MB_WAIT);
473 		if ((m->m_flags & M_EXT) == 0) {
474 			(void) m_free(m);	/* There can be only one. */
475 			return (NULL);
476 		}
477 	}
478 	xs = mtod(m, struct xdr_string *);
479 	m->m_len = mlen;
480 	xs->len = txdr_unsigned(len);
481 	bcopy(str, xs->data, len);
482 	return (m);
483 }
484