FreeBSD/Linux Kernel Cross Reference
sys/rpc/auth_unix.c
1 /* $NetBSD: auth_unix.c,v 1.18 2000/07/06 03:03:30 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2009, Sun Microsystems, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 * - Neither the name of Sun Microsystems, Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #if defined(LIBC_SCCS) && !defined(lint)
32 static char *sccsid2 = "@(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";
33 static char *sccsid = "@(#)auth_unix.c 2.2 88/08/01 4.0 RPCSRC";
34 #endif
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD: releng/11.2/sys/rpc/auth_unix.c 331722 2018-03-29 02:50:57Z eadler $");
37
38 /*
39 * auth_unix.c, Implements UNIX style authentication parameters.
40 *
41 * Copyright (C) 1984, Sun Microsystems, Inc.
42 *
43 * The system is very weak. The client uses no encryption for it's
44 * credentials and only sends null verifiers. The server sends backs
45 * null verifiers or optionally a verifier that suggests a new short hand
46 * for the credentials.
47 *
48 */
49
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/hash.h>
53 #include <sys/kernel.h>
54 #include <sys/lock.h>
55 #include <sys/malloc.h>
56 #include <sys/pcpu.h>
57 #include <sys/refcount.h>
58 #include <sys/sx.h>
59 #include <sys/ucred.h>
60
61 #include <rpc/types.h>
62 #include <rpc/xdr.h>
63 #include <rpc/auth.h>
64 #include <rpc/clnt.h>
65
66 #include <rpc/rpc_com.h>
67
68 /* auth_unix.c */
69 static void authunix_nextverf (AUTH *);
70 static bool_t authunix_marshal (AUTH *, uint32_t, XDR *, struct mbuf *);
71 static bool_t authunix_validate (AUTH *, uint32_t, struct opaque_auth *,
72 struct mbuf **);
73 static bool_t authunix_refresh (AUTH *, void *);
74 static void authunix_destroy (AUTH *);
75 static void marshal_new_auth (AUTH *);
76
77 static struct auth_ops authunix_ops = {
78 .ah_nextverf = authunix_nextverf,
79 .ah_marshal = authunix_marshal,
80 .ah_validate = authunix_validate,
81 .ah_refresh = authunix_refresh,
82 .ah_destroy = authunix_destroy,
83 };
84
85 /*
86 * This struct is pointed to by the ah_private field of an auth_handle.
87 */
88 struct audata {
89 TAILQ_ENTRY(audata) au_link;
90 TAILQ_ENTRY(audata) au_alllink;
91 volatile u_int au_refs;
92 struct xucred au_xcred;
93 struct opaque_auth au_origcred; /* original credentials */
94 struct opaque_auth au_shcred; /* short hand cred */
95 u_long au_shfaults; /* short hand cache faults */
96 char au_marshed[MAX_AUTH_BYTES];
97 u_int au_mpos; /* xdr pos at end of marshed */
98 AUTH *au_auth; /* link back to AUTH */
99 };
100 TAILQ_HEAD(audata_list, audata);
101 #define AUTH_PRIVATE(auth) ((struct audata *)auth->ah_private)
102
103 #define AUTH_UNIX_HASH_SIZE 16
104 #define AUTH_UNIX_MAX 256
105 static struct audata_list auth_unix_cache[AUTH_UNIX_HASH_SIZE];
106 static struct audata_list auth_unix_all;
107 static struct sx auth_unix_lock;
108 static int auth_unix_count;
109
110 static void
111 authunix_init(void *dummy)
112 {
113 int i;
114
115 for (i = 0; i < AUTH_UNIX_HASH_SIZE; i++)
116 TAILQ_INIT(&auth_unix_cache[i]);
117 TAILQ_INIT(&auth_unix_all);
118 sx_init(&auth_unix_lock, "auth_unix_lock");
119 }
120 SYSINIT(authunix_init, SI_SUB_KMEM, SI_ORDER_ANY, authunix_init, NULL);
121
122 /*
123 * Create a unix style authenticator.
124 * Returns an auth handle with the given stuff in it.
125 */
126 AUTH *
127 authunix_create(struct ucred *cred)
128 {
129 uint32_t h, th;
130 struct xucred xcr;
131 char mymem[MAX_AUTH_BYTES];
132 XDR xdrs;
133 AUTH *auth;
134 struct audata *au, *tau;
135 struct timeval now;
136 uint32_t time;
137 int len;
138
139 if (auth_unix_count > AUTH_UNIX_MAX) {
140 while (auth_unix_count > AUTH_UNIX_MAX) {
141 sx_xlock(&auth_unix_lock);
142 tau = TAILQ_FIRST(&auth_unix_all);
143 th = HASHSTEP(HASHINIT, tau->au_xcred.cr_uid)
144 % AUTH_UNIX_HASH_SIZE;
145 TAILQ_REMOVE(&auth_unix_cache[th], tau, au_link);
146 TAILQ_REMOVE(&auth_unix_all, tau, au_alllink);
147 auth_unix_count--;
148 sx_xunlock(&auth_unix_lock);
149 AUTH_DESTROY(tau->au_auth);
150 }
151 }
152
153 /*
154 * Hash the uid to see if we already have an AUTH with this cred.
155 */
156 h = HASHSTEP(HASHINIT, cred->cr_uid) % AUTH_UNIX_HASH_SIZE;
157 cru2x(cred, &xcr);
158 again:
159 sx_slock(&auth_unix_lock);
160 TAILQ_FOREACH(au, &auth_unix_cache[h], au_link) {
161 if (!memcmp(&xcr, &au->au_xcred, sizeof(xcr))) {
162 refcount_acquire(&au->au_refs);
163 if (sx_try_upgrade(&auth_unix_lock)) {
164 /*
165 * Keep auth_unix_all LRU sorted.
166 */
167 TAILQ_REMOVE(&auth_unix_all, au, au_alllink);
168 TAILQ_INSERT_TAIL(&auth_unix_all, au,
169 au_alllink);
170 sx_xunlock(&auth_unix_lock);
171 } else {
172 sx_sunlock(&auth_unix_lock);
173 }
174 return (au->au_auth);
175 }
176 }
177
178 sx_sunlock(&auth_unix_lock);
179
180 /*
181 * Allocate and set up auth handle
182 */
183 au = NULL;
184 auth = mem_alloc(sizeof(*auth));
185 au = mem_alloc(sizeof(*au));
186 auth->ah_ops = &authunix_ops;
187 auth->ah_private = (caddr_t)au;
188 auth->ah_verf = au->au_shcred = _null_auth;
189 refcount_init(&au->au_refs, 1);
190 au->au_xcred = xcr;
191 au->au_shfaults = 0;
192 au->au_origcred.oa_base = NULL;
193 au->au_auth = auth;
194
195 getmicrotime(&now);
196 time = now.tv_sec;
197
198 /*
199 * Serialize the parameters into origcred
200 */
201 xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
202 cru2x(cred, &xcr);
203 if (! xdr_authunix_parms(&xdrs, &time, &xcr))
204 panic("authunix_create: failed to encode creds");
205 au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
206 au->au_origcred.oa_flavor = AUTH_UNIX;
207 au->au_origcred.oa_base = mem_alloc((u_int) len);
208 memcpy(au->au_origcred.oa_base, mymem, (size_t)len);
209
210 /*
211 * set auth handle to reflect new cred.
212 */
213 auth->ah_cred = au->au_origcred;
214 marshal_new_auth(auth);
215
216 sx_xlock(&auth_unix_lock);
217 TAILQ_FOREACH(tau, &auth_unix_cache[h], au_link) {
218 if (!memcmp(&xcr, &tau->au_xcred, sizeof(xcr))) {
219 /*
220 * We lost a race to create the AUTH that
221 * matches this cred.
222 */
223 sx_xunlock(&auth_unix_lock);
224 AUTH_DESTROY(auth);
225 goto again;
226 }
227 }
228
229 auth_unix_count++;
230 TAILQ_INSERT_TAIL(&auth_unix_cache[h], au, au_link);
231 TAILQ_INSERT_TAIL(&auth_unix_all, au, au_alllink);
232 refcount_acquire(&au->au_refs); /* one for the cache, one for user */
233 sx_xunlock(&auth_unix_lock);
234
235 return (auth);
236 }
237
238 /*
239 * authunix operations
240 */
241
242 /* ARGSUSED */
243 static void
244 authunix_nextverf(AUTH *auth)
245 {
246 /* no action necessary */
247 }
248
249 static bool_t
250 authunix_marshal(AUTH *auth, uint32_t xid, XDR *xdrs, struct mbuf *args)
251 {
252 struct audata *au;
253
254 au = AUTH_PRIVATE(auth);
255 if (!XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos))
256 return (FALSE);
257
258 xdrmbuf_append(xdrs, args);
259
260 return (TRUE);
261 }
262
263 static bool_t
264 authunix_validate(AUTH *auth, uint32_t xid, struct opaque_auth *verf,
265 struct mbuf **mrepp)
266 {
267 struct audata *au;
268 XDR txdrs;
269
270 if (!verf)
271 return (TRUE);
272
273 if (verf->oa_flavor == AUTH_SHORT) {
274 au = AUTH_PRIVATE(auth);
275 xdrmem_create(&txdrs, verf->oa_base, verf->oa_length,
276 XDR_DECODE);
277
278 if (au->au_shcred.oa_base != NULL) {
279 mem_free(au->au_shcred.oa_base,
280 au->au_shcred.oa_length);
281 au->au_shcred.oa_base = NULL;
282 }
283 if (xdr_opaque_auth(&txdrs, &au->au_shcred)) {
284 auth->ah_cred = au->au_shcred;
285 } else {
286 txdrs.x_op = XDR_FREE;
287 (void)xdr_opaque_auth(&txdrs, &au->au_shcred);
288 au->au_shcred.oa_base = NULL;
289 auth->ah_cred = au->au_origcred;
290 }
291 marshal_new_auth(auth);
292 }
293
294 return (TRUE);
295 }
296
297 static bool_t
298 authunix_refresh(AUTH *auth, void *dummy)
299 {
300 struct audata *au = AUTH_PRIVATE(auth);
301 struct xucred xcr;
302 uint32_t time;
303 struct timeval now;
304 XDR xdrs;
305 int stat;
306
307 if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
308 /* there is no hope. Punt */
309 return (FALSE);
310 }
311 au->au_shfaults ++;
312
313 /* first deserialize the creds back into a struct ucred */
314 xdrmem_create(&xdrs, au->au_origcred.oa_base,
315 au->au_origcred.oa_length, XDR_DECODE);
316 stat = xdr_authunix_parms(&xdrs, &time, &xcr);
317 if (! stat)
318 goto done;
319
320 /* update the time and serialize in place */
321 getmicrotime(&now);
322 time = now.tv_sec;
323 xdrs.x_op = XDR_ENCODE;
324 XDR_SETPOS(&xdrs, 0);
325
326 stat = xdr_authunix_parms(&xdrs, &time, &xcr);
327 if (! stat)
328 goto done;
329 auth->ah_cred = au->au_origcred;
330 marshal_new_auth(auth);
331 done:
332 XDR_DESTROY(&xdrs);
333 return (stat);
334 }
335
336 static void
337 authunix_destroy(AUTH *auth)
338 {
339 struct audata *au;
340
341 au = AUTH_PRIVATE(auth);
342
343 if (!refcount_release(&au->au_refs))
344 return;
345
346 mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
347
348 if (au->au_shcred.oa_base != NULL)
349 mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
350
351 mem_free(auth->ah_private, sizeof(struct audata));
352
353 if (auth->ah_verf.oa_base != NULL)
354 mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
355
356 mem_free(auth, sizeof(*auth));
357 }
358
359 /*
360 * Marshals (pre-serializes) an auth struct.
361 * sets private data, au_marshed and au_mpos
362 */
363 static void
364 marshal_new_auth(AUTH *auth)
365 {
366 XDR xdr_stream;
367 XDR *xdrs = &xdr_stream;
368 struct audata *au;
369
370 au = AUTH_PRIVATE(auth);
371 xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
372 if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
373 (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
374 printf("auth_none.c - Fatal marshalling problem");
375 else
376 au->au_mpos = XDR_GETPOS(xdrs);
377 XDR_DESTROY(xdrs);
378 }
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