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 * 3. 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, void *);
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, NULL);
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,void * extra __unused)219 recvrpc(struct iodesc *d, void **pkt, void **payload, time_t tleft,
220 void *extra __unused)
221 {
222 void *ptr;
223 struct rpc_reply *reply;
224 ssize_t n;
225 int x;
226
227 errno = 0;
228 #ifdef RPC_DEBUG
229 if (debug)
230 printf("recvrpc: called\n");
231 #endif
232
233 ptr = NULL;
234 n = readudp(d, &ptr, (void **)&reply, tleft);
235 if (n <= (4 * 4)) {
236 free(ptr);
237 return (-1);
238 }
239
240 x = ntohl(reply->rp_xid);
241 if (x != rpc_xid) {
242 #ifdef RPC_DEBUG
243 if (debug)
244 printf("recvrpc: rp_xid %d != xid %d\n", x, rpc_xid);
245 #endif
246 free(ptr);
247 return (-1);
248 }
249
250 x = ntohl(reply->rp_direction);
251 if (x != RPC_REPLY) {
252 #ifdef RPC_DEBUG
253 if (debug)
254 printf("recvrpc: rp_direction %d != REPLY\n", x);
255 #endif
256 free(ptr);
257 return (-1);
258 }
259
260 x = ntohl(reply->rp_astatus);
261 if (x != RPC_MSGACCEPTED) {
262 errno = ntohl(reply->rp_u.rpu_errno);
263 printf("recvrpc: reject, astat=%d, errno=%d\n", x, errno);
264 free(ptr);
265 return (-1);
266 }
267
268 *pkt = ptr;
269 *payload = reply;
270 /* Return data count (thus indicating success) */
271 return (n);
272 }
273
274 /*
275 * Given a pointer to a reply just received,
276 * dig out the IP address/port from the headers.
277 */
278 void
rpc_fromaddr(void * pkt,struct in_addr * addr,u_short * port)279 rpc_fromaddr(void *pkt, struct in_addr *addr, u_short *port)
280 {
281 struct hackhdr {
282 /* Tail of IP header: just IP addresses */
283 n_long ip_src;
284 n_long ip_dst;
285 /* UDP header: */
286 u_int16_t uh_sport; /* source port */
287 u_int16_t uh_dport; /* destination port */
288 int16_t uh_ulen; /* udp length */
289 u_int16_t uh_sum; /* udp checksum */
290 /* RPC reply header: */
291 struct rpc_reply rpc;
292 } *hhdr;
293
294 hhdr = ((struct hackhdr *)pkt) - 1;
295 addr->s_addr = hhdr->ip_src;
296 *port = hhdr->uh_sport;
297 }
298
299 /*
300 * RPC Portmapper cache
301 */
302 #define PMAP_NUM 8 /* need at most 5 pmap entries */
303
304 int rpc_pmap_num;
305 struct pmap_list {
306 struct in_addr addr; /* server, net order */
307 u_int prog; /* host order */
308 u_int vers; /* host order */
309 int port; /* host order */
310 } rpc_pmap_list[PMAP_NUM];
311
312 /*
313 * return port number in host order, or -1.
314 * arguments are:
315 * addr .. server, net order.
316 * prog .. host order.
317 * vers .. host order.
318 */
319 int
rpc_pmap_getcache(struct in_addr addr,u_int prog,u_int vers)320 rpc_pmap_getcache(struct in_addr addr, u_int prog, u_int vers)
321 {
322 struct pmap_list *pl;
323
324 for (pl = rpc_pmap_list; pl < &rpc_pmap_list[rpc_pmap_num]; pl++) {
325 if (pl->addr.s_addr == addr.s_addr &&
326 pl->prog == prog && pl->vers == vers )
327 {
328 return (pl->port);
329 }
330 }
331 return (-1);
332 }
333
334 /*
335 * arguments are:
336 * addr .. server, net order.
337 * prog .. host order.
338 * vers .. host order.
339 * port .. host order.
340 */
341 void
rpc_pmap_putcache(struct in_addr addr,u_int prog,u_int vers,int port)342 rpc_pmap_putcache(struct in_addr addr, u_int prog, u_int vers, int port)
343 {
344 struct pmap_list *pl;
345
346 /* Don't overflow cache... */
347 if (rpc_pmap_num >= PMAP_NUM) {
348 /* ... just re-use the last entry. */
349 rpc_pmap_num = PMAP_NUM - 1;
350 #ifdef RPC_DEBUG
351 printf("rpc_pmap_putcache: cache overflow\n");
352 #endif
353 }
354
355 pl = &rpc_pmap_list[rpc_pmap_num];
356 rpc_pmap_num++;
357
358 /* Cache answer */
359 pl->addr = addr;
360 pl->prog = prog;
361 pl->vers = vers;
362 pl->port = port;
363 }
364
365
366 /*
367 * Request a port number from the port mapper.
368 * Returns the port in host order.
369 * prog and vers are host order.
370 */
371 int
rpc_getport(struct iodesc * d,n_long prog,n_long vers)372 rpc_getport(struct iodesc *d, n_long prog, n_long vers)
373 {
374 struct args {
375 n_long prog; /* call program */
376 n_long vers; /* call version */
377 n_long proto; /* call protocol */
378 n_long port; /* call port (unused) */
379 } *args;
380 struct res {
381 n_long port;
382 } *res;
383 struct {
384 n_long h[RPC_HEADER_WORDS];
385 struct args d;
386 } sdata;
387 void *pkt;
388 ssize_t cc;
389 int port;
390
391 #ifdef RPC_DEBUG
392 if (debug)
393 printf("%s: prog=0x%x vers=%d\n", __func__, prog, vers);
394 #endif
395
396 /* This one is fixed forever. */
397 if (prog == PMAPPROG) {
398 port = PMAPPORT;
399 goto out;
400 }
401
402 /* Try for cached answer first */
403 port = rpc_pmap_getcache(d->destip, prog, vers);
404 if (port != -1)
405 goto out;
406
407 args = &sdata.d;
408 args->prog = htonl(prog);
409 args->vers = htonl(vers);
410 args->proto = htonl(IPPROTO_UDP);
411 args->port = 0;
412 pkt = NULL;
413
414 cc = rpc_call(d, PMAPPROG, PMAPVERS, PMAPPROC_GETPORT,
415 args, sizeof(*args), (void **)&res, &pkt);
416 if (cc < sizeof(*res)) {
417 printf("getport: %s", strerror(errno));
418 errno = EBADRPC;
419 free(pkt);
420 return (-1);
421 }
422 port = (int)ntohl(res->port);
423 free(pkt);
424
425 rpc_pmap_putcache(d->destip, prog, vers, port);
426
427 out:
428 #ifdef RPC_DEBUG
429 if (debug)
430 printf("%s: port=%u\n", __func__, port);
431 #endif
432 return (port);
433 }
434