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
40 /*
41 * RPC functions used by NFS and bootparams.
42 * Note that bootparams requires the ability to find out the
43 * address of the server from which its response has come.
44 * This is supported by keeping the IP/UDP headers in the
45 * buffer space provided by the caller. (See rpc_fromaddr)
46 */
47
48 #include <sys/param.h>
49 #include <sys/socket.h>
50
51 #include <netinet/in.h>
52 #include <netinet/in_systm.h>
53
54 #include <string.h>
55
56 #include "rpcv2.h"
57
58 #include "stand.h"
59 #include "net.h"
60 #include "netif.h"
61 #include "rpc.h"
62
63 struct auth_info {
64 int32_t authtype; /* auth type */
65 u_int32_t authlen; /* auth length */
66 };
67
68 struct auth_unix {
69 int32_t ua_time;
70 int32_t ua_hostname; /* null */
71 int32_t ua_uid;
72 int32_t ua_gid;
73 int32_t ua_gidlist; /* null */
74 };
75
76 struct rpc_call {
77 u_int32_t rp_xid; /* request transaction id */
78 int32_t rp_direction; /* call direction (0) */
79 u_int32_t rp_rpcvers; /* rpc version (2) */
80 u_int32_t rp_prog; /* program */
81 u_int32_t rp_vers; /* version */
82 u_int32_t rp_proc; /* procedure */
83 };
84
85 struct rpc_reply {
86 u_int32_t rp_xid; /* request transaction id */
87 int32_t rp_direction; /* call direction (1) */
88 int32_t rp_astatus; /* accept status (0: accepted) */
89 union {
90 u_int32_t rpu_errno;
91 struct {
92 struct auth_info rok_auth;
93 u_int32_t rok_status;
94 } rpu_rok;
95 } rp_u;
96 };
97
98 /* Local forwards */
99 static ssize_t recvrpc(struct iodesc *, void **, void **, time_t);
100 static int rpc_getport(struct iodesc *, n_long, n_long);
101
102 int rpc_xid;
103 int rpc_port = 0x400; /* predecrement */
104
105 /*
106 * Make a rpc call; return length of answer
107 * Note: Caller must leave room for headers.
108 */
109 ssize_t
rpc_call(struct iodesc * d,n_long prog,n_long vers,n_long proc,void * sdata,size_t slen,void ** rdata,void ** pkt)110 rpc_call(struct iodesc *d, n_long prog, n_long vers, n_long proc,
111 void *sdata, size_t slen, void **rdata, void **pkt)
112 {
113 ssize_t cc, rsize;
114 struct auth_info *auth;
115 struct rpc_call *call;
116 struct rpc_reply *reply;
117 char *send_head, *send_tail;
118 void *ptr;
119 n_long x;
120 int port; /* host order */
121
122 #ifdef RPC_DEBUG
123 if (debug)
124 printf("rpc_call: prog=0x%x vers=%d proc=%d\n",
125 prog, vers, proc);
126 #endif
127
128 port = rpc_getport(d, prog, vers);
129 if (port == -1)
130 return (-1);
131
132 d->destport = htons(port);
133
134 /*
135 * Prepend authorization stuff and headers.
136 * Note, must prepend things in reverse order.
137 */
138 send_head = sdata;
139 send_tail = (char *)sdata + slen;
140
141 /* Auth verifier is always auth_null */
142 send_head -= sizeof(*auth);
143 auth = (struct auth_info *)send_head;
144 auth->authtype = htonl(RPCAUTH_NULL);
145 auth->authlen = 0;
146
147 /* Auth credentials: always auth unix (as root) */
148 send_head -= sizeof(struct auth_unix);
149 bzero(send_head, sizeof(struct auth_unix));
150 send_head -= sizeof(*auth);
151 auth = (struct auth_info *)send_head;
152 auth->authtype = htonl(RPCAUTH_UNIX);
153 auth->authlen = htonl(sizeof(struct auth_unix));
154
155 /* RPC call structure. */
156 send_head -= sizeof(*call);
157 call = (struct rpc_call *)send_head;
158 rpc_xid++;
159 call->rp_xid = htonl(rpc_xid);
160 call->rp_direction = htonl(RPC_CALL);
161 call->rp_rpcvers = htonl(RPC_VER2);
162 call->rp_prog = htonl(prog);
163 call->rp_vers = htonl(vers);
164 call->rp_proc = htonl(proc);
165
166 ptr = NULL;
167 cc = sendrecv(d,
168 sendudp, send_head, send_tail - send_head,
169 recvrpc, &ptr, (void **)&reply);
170
171 #ifdef RPC_DEBUG
172 if (debug)
173 printf("callrpc: cc=%zd\n", cc);
174 #endif
175 if (cc == -1)
176 return (-1);
177
178 if (cc <= sizeof(*reply)) {
179 errno = EBADRPC;
180 free(ptr);
181 return (-1);
182 }
183
184 /*
185 * Check the RPC reply status.
186 * The xid, dir, astatus were already checked.
187 */
188 auth = &reply->rp_u.rpu_rok.rok_auth;
189 x = ntohl(auth->authlen);
190 if (x != 0) {
191 #ifdef RPC_DEBUG
192 if (debug)
193 printf("callrpc: reply auth != NULL\n");
194 #endif
195 errno = EBADRPC;
196 free(ptr);
197 return (-1);
198 }
199 x = ntohl(reply->rp_u.rpu_rok.rok_status);
200 if (x != 0) {
201 printf("callrpc: error = %ld\n", (long)x);
202 errno = EBADRPC;
203 free(ptr);
204 return (-1);
205 }
206
207 rsize = cc - sizeof(*reply);
208 *rdata = (void *)((uintptr_t)reply + sizeof(*reply));
209 *pkt = ptr;
210 return (rsize);
211 }
212
213 /*
214 * Returns true if packet is the one we're waiting for.
215 * This just checks the XID, direction, acceptance.
216 * Remaining checks are done by callrpc
217 */
218 static ssize_t
recvrpc(struct iodesc * d,void ** pkt,void ** payload,time_t tleft)219 recvrpc(struct iodesc *d, void **pkt, void **payload, time_t tleft)
220 {
221 void *ptr;
222 struct rpc_reply *reply;
223 ssize_t n;
224 int x;
225
226 errno = 0;
227 #ifdef RPC_DEBUG
228 if (debug)
229 printf("recvrpc: called\n");
230 #endif
231
232 ptr = NULL;
233 n = readudp(d, &ptr, (void **)&reply, tleft);
234 if (n <= (4 * 4)) {
235 free(ptr);
236 return (-1);
237 }
238
239 x = ntohl(reply->rp_xid);
240 if (x != rpc_xid) {
241 #ifdef RPC_DEBUG
242 if (debug)
243 printf("recvrpc: rp_xid %d != xid %d\n", x, rpc_xid);
244 #endif
245 free(ptr);
246 return (-1);
247 }
248
249 x = ntohl(reply->rp_direction);
250 if (x != RPC_REPLY) {
251 #ifdef RPC_DEBUG
252 if (debug)
253 printf("recvrpc: rp_direction %d != REPLY\n", x);
254 #endif
255 free(ptr);
256 return (-1);
257 }
258
259 x = ntohl(reply->rp_astatus);
260 if (x != RPC_MSGACCEPTED) {
261 errno = ntohl(reply->rp_u.rpu_errno);
262 printf("recvrpc: reject, astat=%d, errno=%d\n", x, errno);
263 free(ptr);
264 return (-1);
265 }
266
267 *pkt = ptr;
268 *payload = reply;
269 /* Return data count (thus indicating success) */
270 return (n);
271 }
272
273 /*
274 * Given a pointer to a reply just received,
275 * dig out the IP address/port from the headers.
276 */
277 void
rpc_fromaddr(void * pkt,struct in_addr * addr,u_short * port)278 rpc_fromaddr(void *pkt, struct in_addr *addr, u_short *port)
279 {
280 struct hackhdr {
281 /* Tail of IP header: just IP addresses */
282 n_long ip_src;
283 n_long ip_dst;
284 /* UDP header: */
285 u_int16_t uh_sport; /* source port */
286 u_int16_t uh_dport; /* destination port */
287 int16_t uh_ulen; /* udp length */
288 u_int16_t uh_sum; /* udp checksum */
289 /* RPC reply header: */
290 struct rpc_reply rpc;
291 } *hhdr;
292
293 hhdr = ((struct hackhdr *)pkt) - 1;
294 addr->s_addr = hhdr->ip_src;
295 *port = hhdr->uh_sport;
296 }
297
298 /*
299 * RPC Portmapper cache
300 */
301 #define PMAP_NUM 8 /* need at most 5 pmap entries */
302
303 int rpc_pmap_num;
304 struct pmap_list {
305 struct in_addr addr; /* server, net order */
306 u_int prog; /* host order */
307 u_int vers; /* host order */
308 int port; /* host order */
309 } rpc_pmap_list[PMAP_NUM];
310
311 /*
312 * return port number in host order, or -1.
313 * arguments are:
314 * addr .. server, net order.
315 * prog .. host order.
316 * vers .. host order.
317 */
318 int
rpc_pmap_getcache(struct in_addr addr,u_int prog,u_int vers)319 rpc_pmap_getcache(struct in_addr addr, u_int prog, u_int vers)
320 {
321 struct pmap_list *pl;
322
323 for (pl = rpc_pmap_list; pl < &rpc_pmap_list[rpc_pmap_num]; pl++) {
324 if (pl->addr.s_addr == addr.s_addr &&
325 pl->prog == prog && pl->vers == vers )
326 {
327 return (pl->port);
328 }
329 }
330 return (-1);
331 }
332
333 /*
334 * arguments are:
335 * addr .. server, net order.
336 * prog .. host order.
337 * vers .. host order.
338 * port .. host order.
339 */
340 void
rpc_pmap_putcache(struct in_addr addr,u_int prog,u_int vers,int port)341 rpc_pmap_putcache(struct in_addr addr, u_int prog, u_int vers, int port)
342 {
343 struct pmap_list *pl;
344
345 /* Don't overflow cache... */
346 if (rpc_pmap_num >= PMAP_NUM) {
347 /* ... just re-use the last entry. */
348 rpc_pmap_num = PMAP_NUM - 1;
349 #ifdef RPC_DEBUG
350 printf("rpc_pmap_putcache: cache overflow\n");
351 #endif
352 }
353
354 pl = &rpc_pmap_list[rpc_pmap_num];
355 rpc_pmap_num++;
356
357 /* Cache answer */
358 pl->addr = addr;
359 pl->prog = prog;
360 pl->vers = vers;
361 pl->port = port;
362 }
363
364
365 /*
366 * Request a port number from the port mapper.
367 * Returns the port in host order.
368 * prog and vers are host order.
369 */
370 int
rpc_getport(struct iodesc * d,n_long prog,n_long vers)371 rpc_getport(struct iodesc *d, n_long prog, n_long vers)
372 {
373 struct args {
374 n_long prog; /* call program */
375 n_long vers; /* call version */
376 n_long proto; /* call protocol */
377 n_long port; /* call port (unused) */
378 } *args;
379 struct res {
380 n_long port;
381 } *res;
382 struct {
383 n_long h[RPC_HEADER_WORDS];
384 struct args d;
385 } sdata;
386 void *pkt;
387 ssize_t cc;
388 int port;
389
390 #ifdef RPC_DEBUG
391 if (debug)
392 printf("%s: prog=0x%x vers=%d\n", __func__, prog, vers);
393 #endif
394
395 /* This one is fixed forever. */
396 if (prog == PMAPPROG) {
397 port = PMAPPORT;
398 goto out;
399 }
400
401 /* Try for cached answer first */
402 port = rpc_pmap_getcache(d->destip, prog, vers);
403 if (port != -1)
404 goto out;
405
406 args = &sdata.d;
407 args->prog = htonl(prog);
408 args->vers = htonl(vers);
409 args->proto = htonl(IPPROTO_UDP);
410 args->port = 0;
411 pkt = NULL;
412
413 cc = rpc_call(d, PMAPPROG, PMAPVERS, PMAPPROC_GETPORT,
414 args, sizeof(*args), (void **)&res, &pkt);
415 if (cc < sizeof(*res)) {
416 printf("getport: %s", strerror(errno));
417 errno = EBADRPC;
418 free(pkt);
419 return (-1);
420 }
421 port = (int)ntohl(res->port);
422 free(pkt);
423
424 rpc_pmap_putcache(d->destip, prog, vers, port);
425
426 out:
427 #ifdef RPC_DEBUG
428 if (debug)
429 printf("%s: port=%u\n", __func__, port);
430 #endif
431 return (port);
432 }
433