xref: /netbsd-src/sys/fs/nfs/common/krpc_subr.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd 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 /* __FBSDID("FreeBSD: head/sys/nfs/krpc_subr.c 248207 2013-03-12 13:42:47Z glebius "); */
47 __RCSID("$NetBSD: krpc_subr.c,v 1.3 2015/02/07 12:50:25 mlelstv Exp $");
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/jail.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/proc.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
57 #include <sys/uio.h>
58 
59 #include <net/if.h>
60 #include <net/vnet.h>
61 
62 #include <netinet/in.h>
63 
64 #include <rpc/types.h>
65 #include <rpc/auth.h>
66 #include <rpc/rpc_msg.h>
67 #include <nfs/krpc.h>
68 #include <nfs/xdr_subs.h>
69 
70 /*
71  * Kernel support for Sun RPC
72  *
73  * Used currently for bootstrapping in nfs diskless configurations.
74  */
75 
76 /*
77  * Generic RPC headers
78  */
79 
80 struct auth_info {
81 	u_int32_t 	authtype;	/* auth type */
82 	u_int32_t	authlen;	/* auth length */
83 };
84 
85 struct auth_unix {
86 	int32_t   ua_time;
87 	int32_t   ua_hostname;	/* null */
88 	int32_t   ua_uid;
89 	int32_t   ua_gid;
90 	int32_t   ua_gidlist;	/* null */
91 };
92 
93 struct krpc_call {
94 	u_int32_t	rp_xid;		/* request transaction id */
95 	int32_t 	rp_direction;	/* call direction (0) */
96 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
97 	u_int32_t	rp_prog;	/* program */
98 	u_int32_t	rp_vers;	/* version */
99 	u_int32_t	rp_proc;	/* procedure */
100 	struct	auth_info rpc_auth;
101 	struct	auth_unix rpc_unix;
102 	struct	auth_info rpc_verf;
103 };
104 
105 struct krpc_reply {
106 	u_int32_t rp_xid;		/* request transaction id */
107 	int32_t  rp_direction;		/* call direction (1) */
108 	int32_t  rp_astatus;		/* accept status (0: accepted) */
109 	union {
110 		u_int32_t rpu_errno;
111 		struct {
112 			struct auth_info rok_auth;
113 			u_int32_t	rok_status;
114 		} rpu_rok;
115 	} rp_u;
116 };
117 #define rp_errno  rp_u.rpu_errno
118 #define rp_auth   rp_u.rpu_rok.rok_auth
119 #define rp_status rp_u.rpu_rok.rok_status
120 
121 #define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
122 
123 /*
124  * What is the longest we will wait before re-sending a request?
125  * Note this is also the frequency of "RPC timeout" messages.
126  * The re-send loop count sup linearly to this maximum, so the
127  * first complaint will happen after (1+2+3+4+5)=15 seconds.
128  */
129 #define	MAX_RESEND_DELAY 5	/* seconds */
130 
131 /*
132  * Call portmap to lookup a port number for a particular rpc program
133  * Returns non-zero error on failure.
134  */
135 int
136 krpc_portmap(struct sockaddr_in *sin, u_int prog, u_int vers, u_int16_t *portp,
137     struct thread *td)
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_WAITOK, 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(IPPROTO_UDP);
166 	sdata->port = 0;
167 
168 	sin->sin_port = htons(PMAPPORT);
169 	error = krpc_call(sin, PMAPPROG, PMAPVERS,
170 					  PMAPPROC_GETPORT, &m, NULL, td);
171 	if (error)
172 		goto out;
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 out:
183 	m_freem(m);
184 	return error;
185 }
186 
187 /*
188  * Do a remote procedure call (RPC) and wait for its reply.
189  * If from_p is non-null, then we are doing broadcast, and
190  * the address from whence the response came is saved there.
191  */
192 int
193 krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
194     struct mbuf **data, struct sockaddr **from_p, struct thread *td)
195 {
196 	struct socket *so;
197 	struct sockaddr_in *sin, ssin;
198 	struct sockaddr *from;
199 	struct mbuf *m, *nam, *mhead;
200 	struct krpc_call *call;
201 	struct krpc_reply *reply;
202 	struct sockopt sopt;
203 	struct timeval tv;
204 	struct uio auio;
205 	int error, rcvflg, timo, secs, len;
206 	static u_int32_t xid = ~0xFF;
207 	u_int16_t tport;
208 	u_int32_t saddr;
209 
210 	/*
211 	 * Validate address family.
212 	 * Sorry, this is INET specific...
213 	 */
214 	if (sa->sin_family != AF_INET)
215 		return (EAFNOSUPPORT);
216 
217 	/* Free at end if not null. */
218 	nam = mhead = NULL;
219 	from = NULL;
220 
221 	/*
222 	 * Create socket and set its recieve timeout.
223 	 */
224 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td->td_ucred, td)))
225 		goto out;
226 
227 	tv.tv_sec = 1;
228 	tv.tv_usec = 0;
229 	bzero(&sopt, sizeof sopt);
230 	sopt.sopt_dir = SOPT_SET;
231 	sopt.sopt_level = SOL_SOCKET;
232 	sopt.sopt_name = SO_RCVTIMEO;
233 	sopt.sopt_val = &tv;
234 	sopt.sopt_valsize = sizeof tv;
235 
236 	if ((error = sosetopt(so, &sopt)) != 0)
237 		goto out;
238 
239 	/*
240 	 * Enable broadcast if necessary.
241 	 */
242 	if (from_p) {
243 		int on = 1;
244 		sopt.sopt_name = SO_BROADCAST;
245 		sopt.sopt_val = &on;
246 		sopt.sopt_valsize = sizeof on;
247 		if ((error = sosetopt(so, &sopt)) != 0)
248 			goto out;
249 	}
250 
251 	/*
252 	 * Bind the local endpoint to a reserved port,
253 	 * because some NFS servers refuse requests from
254 	 * non-reserved (non-privileged) ports.
255 	 */
256 	sin = &ssin;
257 	bzero(sin, sizeof *sin);
258 	sin->sin_len = sizeof(*sin);
259 	sin->sin_family = AF_INET;
260 	sin->sin_addr.s_addr = INADDR_ANY;
261 	tport = IPPORT_RESERVED;
262 	do {
263 		tport--;
264 		sin->sin_port = htons(tport);
265 		error = sobind(so, (struct sockaddr *)sin, td);
266 	} while (error == EADDRINUSE &&
267 			 tport > IPPORT_RESERVED / 2);
268 	if (error) {
269 		printf("bind failed\n");
270 		goto out;
271 	}
272 
273 	/*
274 	 * Setup socket address for the server.
275 	 */
276 
277 	/*
278 	 * Prepend RPC message header.
279 	 */
280 	mhead = m_gethdr(M_WAITOK, MT_DATA);
281 	mhead->m_next = *data;
282 	*data = NULL;
283 	call = mtod(mhead, struct krpc_call *);
284 	mhead->m_len = sizeof(*call);
285 	bzero((caddr_t)call, sizeof(*call));
286 	/* rpc_call part */
287 	xid++;
288 	call->rp_xid = txdr_unsigned(xid);
289 	/* call->rp_direction = 0; */
290 	call->rp_rpcvers = txdr_unsigned(2);
291 	call->rp_prog = txdr_unsigned(prog);
292 	call->rp_vers = txdr_unsigned(vers);
293 	call->rp_proc = txdr_unsigned(func);
294 	/* rpc_auth part (auth_unix as root) */
295 	call->rpc_auth.authtype = txdr_unsigned(AUTH_UNIX);
296 	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
297 	/* rpc_verf part (auth_null) */
298 	call->rpc_verf.authtype = 0;
299 	call->rpc_verf.authlen  = 0;
300 
301 	/*
302 	 * Setup packet header
303 	 */
304 	m_fixhdr(mhead);
305 	mhead->m_pkthdr.rcvif = NULL;
306 
307 	/*
308 	 * Send it, repeatedly, until a reply is received,
309 	 * but delay each re-send by an increasing amount.
310 	 * If the delay hits the maximum, start complaining.
311 	 */
312 	timo = 0;
313 	for (;;) {
314 		/* Send RPC request (or re-send). */
315 		m = m_copym(mhead, 0, M_COPYALL, M_WAITOK);
316 		error = sosend(so, (struct sockaddr *)sa, NULL, m,
317 			       NULL, 0, td);
318 		if (error) {
319 			printf("krpc_call: sosend: %d\n", error);
320 			goto out;
321 		}
322 		m = NULL;
323 
324 		/* Determine new timeout. */
325 		if (timo < MAX_RESEND_DELAY)
326 			timo++;
327 		else {
328 			saddr = ntohl(sa->sin_addr.s_addr);
329 			printf("RPC timeout for server %d.%d.%d.%d\n",
330 			       (saddr >> 24) & 255,
331 			       (saddr >> 16) & 255,
332 			       (saddr >> 8) & 255,
333 			       saddr & 255);
334 		}
335 
336 		/*
337 		 * Wait for up to timo seconds for a reply.
338 		 * The socket receive timeout was set to 1 second.
339 		 */
340 		secs = timo;
341 		while (secs > 0) {
342 			if (from) {
343 				free(from, M_SONAME);
344 				from = NULL;
345 			}
346 			if (m) {
347 				m_freem(m);
348 				m = NULL;
349 			}
350 			bzero(&auio, sizeof(auio));
351 			auio.uio_resid = len = 1<<16;
352 			rcvflg = 0;
353 			error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
354 			if (error == EWOULDBLOCK) {
355 				secs--;
356 				continue;
357 			}
358 			if (error)
359 				goto out;
360 			len -= auio.uio_resid;
361 
362 			/* Does the reply contain at least a header? */
363 			if (len < MIN_REPLY_HDR)
364 				continue;
365 			if (m->m_len < MIN_REPLY_HDR)
366 				continue;
367 			reply = mtod(m, struct krpc_reply *);
368 
369 			/* Is it the right reply? */
370 			if (reply->rp_direction != txdr_unsigned(REPLY))
371 				continue;
372 
373 			if (reply->rp_xid != txdr_unsigned(xid))
374 				continue;
375 
376 			/* Was RPC accepted? (authorization OK) */
377 			if (reply->rp_astatus != 0) {
378 				error = fxdr_unsigned(u_int32_t, reply->rp_errno);
379 				printf("rpc denied, error=%d\n", error);
380 				continue;
381 			}
382 
383 			/* Did the call succeed? */
384 			if (reply->rp_status != 0) {
385 				error = fxdr_unsigned(u_int32_t, reply->rp_status);
386 				if (error == PROG_MISMATCH) {
387 				  error = EBADRPC;
388 				  goto out;
389 				}
390 				printf("rpc denied, status=%d\n", error);
391 				continue;
392 			}
393 
394 			goto gotreply;	/* break two levels */
395 
396 		} /* while secs */
397 	} /* forever send/receive */
398 
399 	error = ETIMEDOUT;
400 	goto out;
401 
402  gotreply:
403 
404 	/*
405 	 * Get RPC reply header into first mbuf,
406 	 * get its length, then strip it off.
407 	 */
408 	len = sizeof(*reply);
409 	if (m->m_len < len) {
410 		m = m_pullup(m, len);
411 		if (m == NULL) {
412 			error = ENOBUFS;
413 			goto out;
414 		}
415 	}
416 	reply = mtod(m, struct krpc_reply *);
417 	if (reply->rp_auth.authtype != 0) {
418 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
419 		len = (len + 3) & ~3; /* XXX? */
420 	}
421 	m_adj(m, len);
422 
423 	/* result */
424 	*data = m;
425 	if (from_p) {
426 		*from_p = from;
427 		from = NULL;
428 	}
429 
430  out:
431 	if (mhead) m_freem(mhead);
432 	if (from) free(from, M_SONAME);
433 	soclose(so);
434 	return error;
435 }
436 
437 /*
438  * eXternal Data Representation routines.
439  * (but with non-standard args...)
440  */
441 
442 /*
443  * String representation for RPC.
444  */
445 struct xdr_string {
446 	u_int32_t len;		/* length without null or padding */
447 	char data[4];	/* data (longer, of course) */
448     /* data is padded to a long-word boundary */
449 };
450 
451 struct mbuf *
452 xdr_string_encode(char *str, int len)
453 {
454 	struct mbuf *m;
455 	struct xdr_string *xs;
456 	int dlen;	/* padded string length */
457 	int mlen;	/* message length */
458 
459 	dlen = (len + 3) & ~3;
460 	mlen = dlen + 4;
461 
462 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
463 		return (NULL);
464 
465 	m = m_get2(mlen, M_WAITOK, MT_DATA, 0);
466 	xs = mtod(m, struct xdr_string *);
467 	m->m_len = mlen;
468 	xs->len = txdr_unsigned(len);
469 	bcopy(str, xs->data, len);
470 	return (m);
471 }
472