rpc.c revision 165906 
1/*	$NetBSD: rpc.c,v 1.18 1998/01/23 19:27:45 thorpej Exp $	*/
2
3/*
4 * Copyright (c) 1992 Regents of the University of California.
5 * All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/lib/libstand/rpc.c 165906 2007-01-09 01:02:06Z imp $");
40
41/*
42 * RPC functions used by NFS and bootparams.
43 * Note that bootparams requires the ability to find out the
44 * address of the server from which its response has come.
45 * This is supported by keeping the IP/UDP headers in the
46 * buffer space provided by the caller.  (See rpc_fromaddr)
47 */
48
49#include <sys/param.h>
50#include <sys/socket.h>
51
52#include <netinet/in.h>
53#include <netinet/in_systm.h>
54
55#include <string.h>
56
57#include "rpcv2.h"
58
59#include "stand.h"
60#include "net.h"
61#include "netif.h"
62#include "rpc.h"
63
64struct auth_info {
65	int32_t 	authtype;	/* auth type */
66	u_int32_t	authlen;	/* auth length */
67};
68
69struct 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
77struct 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
86struct 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 */
100static	ssize_t recvrpc(struct iodesc *, void *, size_t, time_t);
101static	int rpc_getport(struct iodesc *, n_long, n_long);
102
103int rpc_xid;
104int rpc_port = 0x400;	/* predecrement */
105
106/*
107 * Make a rpc call; return length of answer
108 * Note: Caller must leave room for headers.
109 */
110ssize_t
111rpc_call(d, prog, vers, proc, sdata, slen, rdata, rlen)
112	struct iodesc *d;
113	n_long prog, vers, proc;
114	void *sdata;
115	size_t slen;
116	void *rdata;
117	size_t rlen;
118{
119	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=%ld rlen=%lu\n", (long)cc, (u_long)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 = %ld\n", (long)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 */
234static ssize_t
235recvrpc(d, pkt, len, tleft)
236	struct iodesc *d;
237	void *pkt;
238	size_t len;
239	time_t tleft;
240{
241	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=%lu\n", (u_long)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 %d != 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 %d != 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 */
290void
291rpc_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
319int rpc_pmap_num;
320struct 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 */
328int
329rpc_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
346void
347rpc_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 */
379int
380rpc_getport(d, prog, vers)
381	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