xref: /openbsd/sys/lib/libsa/rpc.c (revision 07ea8d15)
1 /*	$OpenBSD: rpc.c,v 1.8 1996/12/12 08:35:38 mickey Exp $	*/
2 /*	$NetBSD: rpc.c,v 1.16 1996/10/13 02:29:06 christos Exp $	*/
3 
4 /*
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  * @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
41  */
42 
43 /*
44  * RPC functions used by NFS and bootparams.
45  * Note that bootparams requires the ability to find out the
46  * address of the server from which its response has come.
47  * This is supported by keeping the IP/UDP headers in the
48  * buffer space provided by the caller.  (See rpc_fromaddr)
49  */
50 
51 #include <sys/param.h>
52 #include <sys/socket.h>
53 
54 #include <netinet/in.h>
55 #include <netinet/in_systm.h>
56 
57 #include <nfs/rpcv2.h>
58 
59 #include "stand.h"
60 #include "net.h"
61 #include "netif.h"
62 #include "rpc.h"
63 
64 struct auth_info {
65 	int32_t 	authtype;	/* auth type */
66 	u_int32_t	authlen;	/* auth length */
67 };
68 
69 struct auth_unix {
70 	int32_t   ua_time;
71 	int32_t   ua_hostname;	/* null */
72 	int32_t   ua_uid;
73 	int32_t   ua_gid;
74 	int32_t   ua_gidlist;	/* null */
75 };
76 
77 struct rpc_call {
78 	u_int32_t	rp_xid;		/* request transaction id */
79 	int32_t 	rp_direction;	/* call direction (0) */
80 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
81 	u_int32_t	rp_prog;	/* program */
82 	u_int32_t	rp_vers;	/* version */
83 	u_int32_t	rp_proc;	/* procedure */
84 };
85 
86 struct rpc_reply {
87 	u_int32_t	rp_xid;		/* request transaction id */
88 	int32_t 	rp_direction;	/* call direction (1) */
89 	int32_t 	rp_astatus;	/* accept status (0: accepted) */
90 	union {
91 		u_int32_t	rpu_errno;
92 		struct {
93 			struct auth_info rok_auth;
94 			u_int32_t	rok_status;
95 		} rpu_rok;
96 	} rp_u;
97 };
98 
99 /* Local forwards */
100 static	ssize_t recvrpc __P((struct iodesc *, void *, size_t, time_t));
101 static	int rpc_getport __P((struct iodesc *, n_long, n_long));
102 
103 int rpc_xid;
104 int rpc_port = 0x400;	/* predecrement */
105 
106 /*
107  * Make a rpc call; return length of answer
108  * Note: Caller must leave room for headers.
109  */
110 ssize_t
111 rpc_call(d, prog, vers, proc, sdata, slen, rdata, rlen)
112 	register struct iodesc *d;
113 	register n_long prog, vers, proc;
114 	register void *sdata;
115 	register size_t slen;
116 	register void *rdata;
117 	register size_t rlen;
118 {
119 	register ssize_t cc;
120 	struct auth_info *auth;
121 	struct rpc_call *call;
122 	struct rpc_reply *reply;
123 	char *send_head, *send_tail;
124 	char *recv_head, *recv_tail;
125 	n_long x;
126 	int port;	/* host order */
127 
128 #ifdef RPC_DEBUG
129 	if (debug)
130 		printf("rpc_call: prog=0x%x vers=%d proc=%d\n",
131 		    prog, vers, proc);
132 #endif
133 
134 	port = rpc_getport(d, prog, vers);
135 	if (port == -1)
136 		return (-1);
137 
138 	d->destport = htons(port);
139 
140 	/*
141 	 * Prepend authorization stuff and headers.
142 	 * Note, must prepend things in reverse order.
143 	 */
144 	send_head = sdata;
145 	send_tail = (char *)sdata + slen;
146 
147 	/* Auth verifier is always auth_null */
148 	send_head -= sizeof(*auth);
149 	auth = (struct auth_info *)send_head;
150 	auth->authtype = htonl(RPCAUTH_NULL);
151 	auth->authlen = 0;
152 
153 #if 1
154 	/* Auth credentials: always auth unix (as root) */
155 	send_head -= sizeof(struct auth_unix);
156 	bzero(send_head, sizeof(struct auth_unix));
157 	send_head -= sizeof(*auth);
158 	auth = (struct auth_info *)send_head;
159 	auth->authtype = htonl(RPCAUTH_UNIX);
160 	auth->authlen = htonl(sizeof(struct auth_unix));
161 #else
162 	/* Auth credentials: always auth_null (XXX OK?) */
163 	send_head -= sizeof(*auth);
164 	auth = send_head;
165 	auth->authtype = htonl(RPCAUTH_NULL);
166 	auth->authlen = 0;
167 #endif
168 
169 	/* RPC call structure. */
170 	send_head -= sizeof(*call);
171 	call = (struct rpc_call *)send_head;
172 	rpc_xid++;
173 	call->rp_xid       = htonl(rpc_xid);
174 	call->rp_direction = htonl(RPC_CALL);
175 	call->rp_rpcvers   = htonl(RPC_VER2);
176 	call->rp_prog = htonl(prog);
177 	call->rp_vers = htonl(vers);
178 	call->rp_proc = htonl(proc);
179 
180 	/* Make room for the rpc_reply header. */
181 	recv_head = rdata;
182 	recv_tail = (char *)rdata + rlen;
183 	recv_head -= sizeof(*reply);
184 
185 	cc = sendrecv(d,
186 	    sendudp, send_head, send_tail - send_head,
187 	    recvrpc, recv_head, recv_tail - recv_head);
188 
189 #ifdef RPC_DEBUG
190 	if (debug)
191 		printf("callrpc: cc=%d rlen=%d\n", cc, rlen);
192 #endif
193 	if (cc == -1)
194 		return (-1);
195 
196 	if (cc <= sizeof(*reply)) {
197 		errno = EBADRPC;
198 		return (-1);
199 	}
200 
201 	recv_tail = recv_head + cc;
202 
203 	/*
204 	 * Check the RPC reply status.
205 	 * The xid, dir, astatus were already checked.
206 	 */
207 	reply = (struct rpc_reply *)recv_head;
208 	auth = &reply->rp_u.rpu_rok.rok_auth;
209 	x = ntohl(auth->authlen);
210 	if (x != 0) {
211 #ifdef RPC_DEBUG
212 		if (debug)
213 			printf("callrpc: reply auth != NULL\n");
214 #endif
215 		errno = EBADRPC;
216 		return(-1);
217 	}
218 	x = ntohl(reply->rp_u.rpu_rok.rok_status);
219 	if (x != 0) {
220 		printf("callrpc: error = %d\n", x);
221 		errno = EBADRPC;
222 		return(-1);
223 	}
224 	recv_head += sizeof(*reply);
225 
226 	return (ssize_t)(recv_tail - recv_head);
227 }
228 
229 /*
230  * Returns true if packet is the one we're waiting for.
231  * This just checks the XID, direction, acceptance.
232  * Remaining checks are done by callrpc
233  */
234 static ssize_t
235 recvrpc(d, pkt, len, tleft)
236 	register struct iodesc *d;
237 	register void *pkt;
238 	register size_t len;
239 	time_t tleft;
240 {
241 	register struct rpc_reply *reply;
242 	ssize_t	n;
243 	int	x;
244 
245 	errno = 0;
246 #ifdef RPC_DEBUG
247 	if (debug)
248 		printf("recvrpc: called len=%d\n", len);
249 #endif
250 
251 	n = readudp(d, pkt, len, tleft);
252 	if (n <= (4 * 4))
253 		return -1;
254 
255 	reply = (struct rpc_reply *)pkt;
256 
257 	x = ntohl(reply->rp_xid);
258 	if (x != rpc_xid) {
259 #ifdef RPC_DEBUG
260 		if (debug)
261 			printf("recvrpc: rp_xid %ld != xid %d\n", x, rpc_xid);
262 #endif
263 		return -1;
264 	}
265 
266 	x = ntohl(reply->rp_direction);
267 	if (x != RPC_REPLY) {
268 #ifdef RPC_DEBUG
269 		if (debug)
270 			printf("recvrpc: rp_direction %ld != REPLY\n", x);
271 #endif
272 		return -1;
273 	}
274 
275 	x = ntohl(reply->rp_astatus);
276 	if (x != RPC_MSGACCEPTED) {
277 		errno = ntohl(reply->rp_u.rpu_errno);
278 		printf("recvrpc: reject, astat=%d, errno=%d\n", x, errno);
279 		return -1;
280 	}
281 
282 	/* Return data count (thus indicating success) */
283 	return (n);
284 }
285 
286 /*
287  * Given a pointer to a reply just received,
288  * dig out the IP address/port from the headers.
289  */
290 void
291 rpc_fromaddr(pkt, addr, port)
292 	void		*pkt;
293 	struct in_addr	*addr;
294 	u_short		*port;
295 {
296 	struct hackhdr {
297 		/* Tail of IP header: just IP addresses */
298 		n_long ip_src;
299 		n_long ip_dst;
300 		/* UDP header: */
301 		u_int16_t uh_sport;		/* source port */
302 		u_int16_t uh_dport;		/* destination port */
303 		int16_t	  uh_ulen;		/* udp length */
304 		u_int16_t uh_sum;		/* udp checksum */
305 		/* RPC reply header: */
306 		struct rpc_reply rpc;
307 	} *hhdr;
308 
309 	hhdr = ((struct hackhdr *)pkt) - 1;
310 	addr->s_addr = hhdr->ip_src;
311 	*port = hhdr->uh_sport;
312 }
313 
314 /*
315  * RPC Portmapper cache
316  */
317 #define PMAP_NUM 8			/* need at most 5 pmap entries */
318 
319 int rpc_pmap_num;
320 struct pmap_list {
321 	struct in_addr	addr;	/* server, net order */
322 	u_int	prog;		/* host order */
323 	u_int	vers;		/* host order */
324 	int 	port;		/* host order */
325 } rpc_pmap_list[PMAP_NUM];
326 
327 /* return port number in host order, or -1 */
328 int
329 rpc_pmap_getcache(addr, prog, vers)
330 	struct in_addr	addr;	/* server, net order */
331 	u_int		prog;	/* host order */
332 	u_int		vers;	/* host order */
333 {
334 	struct pmap_list *pl;
335 
336 	for (pl = rpc_pmap_list; pl < &rpc_pmap_list[rpc_pmap_num]; pl++) {
337 		if (pl->addr.s_addr == addr.s_addr &&
338 			pl->prog == prog && pl->vers == vers )
339 		{
340 			return (pl->port);
341 		}
342 	}
343 	return (-1);
344 }
345 
346 void
347 rpc_pmap_putcache(addr, prog, vers, port)
348 	struct in_addr	addr;	/* server, net order */
349 	u_int		prog;	/* host order */
350 	u_int		vers;	/* host order */
351 	int 		port;	/* host order */
352 {
353 	struct pmap_list *pl;
354 
355 	/* Don't overflow cache... */
356 	if (rpc_pmap_num >= PMAP_NUM) {
357 		/* ... just re-use the last entry. */
358 		rpc_pmap_num = PMAP_NUM - 1;
359 #ifdef	RPC_DEBUG
360 		printf("rpc_pmap_putcache: cache overflow\n");
361 #endif
362 	}
363 
364 	pl = &rpc_pmap_list[rpc_pmap_num];
365 	rpc_pmap_num++;
366 
367 	/* Cache answer */
368 	pl->addr = addr;
369 	pl->prog = prog;
370 	pl->vers = vers;
371 	pl->port = port;
372 }
373 
374 
375 /*
376  * Request a port number from the port mapper.
377  * Returns the port in host order.
378  */
379 int
380 rpc_getport(d, prog, vers)
381 	register struct iodesc *d;
382 	n_long prog;	/* host order */
383 	n_long vers;	/* host order */
384 {
385 	struct args {
386 		n_long	prog;		/* call program */
387 		n_long	vers;		/* call version */
388 		n_long	proto;		/* call protocol */
389 		n_long	port;		/* call port (unused) */
390 	} *args;
391 	struct res {
392 		n_long port;
393 	} *res;
394 	struct {
395 		n_long	h[RPC_HEADER_WORDS];
396 		struct args d;
397 	} sdata;
398 	struct {
399 		n_long	h[RPC_HEADER_WORDS];
400 		struct res d;
401 		n_long  pad;
402 	} rdata;
403 	ssize_t cc;
404 	int port;
405 
406 #ifdef RPC_DEBUG
407 	if (debug)
408 		printf("getport: prog=0x%x vers=%d\n", prog, vers);
409 #endif
410 
411 	/* This one is fixed forever. */
412 	if (prog == PMAPPROG)
413 		return (PMAPPORT);
414 
415 	/* Try for cached answer first */
416 	port = rpc_pmap_getcache(d->destip, prog, vers);
417 	if (port != -1)
418 		return (port);
419 
420 	args = &sdata.d;
421 	args->prog = htonl(prog);
422 	args->vers = htonl(vers);
423 	args->proto = htonl(IPPROTO_UDP);
424 	args->port = 0;
425 	res = &rdata.d;
426 
427 	cc = rpc_call(d, PMAPPROG, PMAPVERS, PMAPPROC_GETPORT,
428 		args, sizeof(*args), res, sizeof(*res));
429 	if (cc < sizeof(*res)) {
430 		printf("getport: %s", strerror(errno));
431 		errno = EBADRPC;
432 		return (-1);
433 	}
434 	port = (int)ntohl(res->port);
435 
436 	rpc_pmap_putcache(d->destip, prog, vers, port);
437 
438 	return (port);
439 }
440