1 /* $NetBSD: auth_unix.c,v 1.18 2000/07/06 03:03:30 christos Exp $ */ 2 3 /* 4 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for 5 * unrestricted use provided that this legend is included on all tape 6 * media and as a part of the software program in whole or part. Users 7 * may copy or modify Sun RPC without charge, but are not authorized 8 * to license or distribute it to anyone else except as part of a product or 9 * program developed by the user. 10 * 11 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE 12 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR 13 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. 14 * 15 * Sun RPC is provided with no support and without any obligation on the 16 * part of Sun Microsystems, Inc. to assist in its use, correction, 17 * modification or enhancement. 18 * 19 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE 20 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC 21 * OR ANY PART THEREOF. 22 * 23 * In no event will Sun Microsystems, Inc. be liable for any lost revenue 24 * or profits or other special, indirect and consequential damages, even if 25 * Sun has been advised of the possibility of such damages. 26 * 27 * Sun Microsystems, Inc. 28 * 2550 Garcia Avenue 29 * Mountain View, California 94043 30 */ 31 32 #if defined(LIBC_SCCS) && !defined(lint) 33 static char *sccsid2 = "@(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro"; 34 static char *sccsid = "@(#)auth_unix.c 2.2 88/08/01 4.0 RPCSRC"; 35 #endif 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 /* 40 * auth_unix.c, Implements UNIX style authentication parameters. 41 * 42 * Copyright (C) 1984, Sun Microsystems, Inc. 43 * 44 * The system is very weak. The client uses no encryption for it's 45 * credentials and only sends null verifiers. The server sends backs 46 * null verifiers or optionally a verifier that suggests a new short hand 47 * for the credentials. 48 * 49 */ 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/hash.h> 54 #include <sys/kernel.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/pcpu.h> 58 #include <sys/refcount.h> 59 #include <sys/sx.h> 60 #include <sys/ucred.h> 61 62 #include <rpc/types.h> 63 #include <rpc/xdr.h> 64 #include <rpc/auth.h> 65 #include <rpc/clnt.h> 66 67 #include <rpc/rpc_com.h> 68 69 /* auth_unix.c */ 70 static void authunix_nextverf (AUTH *); 71 static bool_t authunix_marshal (AUTH *, uint32_t, XDR *, struct mbuf *); 72 static bool_t authunix_validate (AUTH *, uint32_t, struct opaque_auth *, 73 struct mbuf **); 74 static bool_t authunix_refresh (AUTH *, void *); 75 static void authunix_destroy (AUTH *); 76 static void marshal_new_auth (AUTH *); 77 78 static struct auth_ops authunix_ops = { 79 .ah_nextverf = authunix_nextverf, 80 .ah_marshal = authunix_marshal, 81 .ah_validate = authunix_validate, 82 .ah_refresh = authunix_refresh, 83 .ah_destroy = authunix_destroy, 84 }; 85 86 /* 87 * This struct is pointed to by the ah_private field of an auth_handle. 88 */ 89 struct audata { 90 TAILQ_ENTRY(audata) au_link; 91 TAILQ_ENTRY(audata) au_alllink; 92 volatile u_int au_refs; 93 struct xucred au_xcred; 94 struct opaque_auth au_origcred; /* original credentials */ 95 struct opaque_auth au_shcred; /* short hand cred */ 96 u_long au_shfaults; /* short hand cache faults */ 97 char au_marshed[MAX_AUTH_BYTES]; 98 u_int au_mpos; /* xdr pos at end of marshed */ 99 AUTH *au_auth; /* link back to AUTH */ 100 }; 101 TAILQ_HEAD(audata_list, audata); 102 #define AUTH_PRIVATE(auth) ((struct audata *)auth->ah_private) 103 104 #define AUTH_UNIX_HASH_SIZE 16 105 #define AUTH_UNIX_MAX 256 106 static struct audata_list auth_unix_cache[AUTH_UNIX_HASH_SIZE]; 107 static struct audata_list auth_unix_all; 108 static struct sx auth_unix_lock; 109 static int auth_unix_count; 110 111 static void 112 authunix_init(void *dummy) 113 { 114 int i; 115 116 for (i = 0; i < AUTH_UNIX_HASH_SIZE; i++) 117 TAILQ_INIT(&auth_unix_cache[i]); 118 TAILQ_INIT(&auth_unix_all); 119 sx_init(&auth_unix_lock, "auth_unix_lock"); 120 } 121 SYSINIT(authunix_init, SI_SUB_KMEM, SI_ORDER_ANY, authunix_init, NULL); 122 123 /* 124 * Create a unix style authenticator. 125 * Returns an auth handle with the given stuff in it. 126 */ 127 AUTH * 128 authunix_create(struct ucred *cred) 129 { 130 uint32_t h, th; 131 struct xucred xcr; 132 char mymem[MAX_AUTH_BYTES]; 133 XDR xdrs; 134 AUTH *auth; 135 struct audata *au, *tau; 136 struct timeval now; 137 uint32_t time; 138 int len; 139 140 if (auth_unix_count > AUTH_UNIX_MAX) { 141 while (auth_unix_count > AUTH_UNIX_MAX) { 142 sx_xlock(&auth_unix_lock); 143 tau = TAILQ_FIRST(&auth_unix_all); 144 th = HASHSTEP(HASHINIT, tau->au_xcred.cr_uid) 145 % AUTH_UNIX_HASH_SIZE; 146 TAILQ_REMOVE(&auth_unix_cache[th], tau, au_link); 147 TAILQ_REMOVE(&auth_unix_all, tau, au_alllink); 148 auth_unix_count--; 149 sx_xunlock(&auth_unix_lock); 150 AUTH_DESTROY(tau->au_auth); 151 } 152 } 153 154 /* 155 * Hash the uid to see if we already have an AUTH with this cred. 156 */ 157 h = HASHSTEP(HASHINIT, cred->cr_uid) % AUTH_UNIX_HASH_SIZE; 158 cru2x(cred, &xcr); 159 again: 160 sx_slock(&auth_unix_lock); 161 TAILQ_FOREACH(au, &auth_unix_cache[h], au_link) { 162 if (!memcmp(&xcr, &au->au_xcred, sizeof(xcr))) { 163 refcount_acquire(&au->au_refs); 164 if (sx_try_upgrade(&auth_unix_lock)) { 165 /* 166 * Keep auth_unix_all LRU sorted. 167 */ 168 TAILQ_REMOVE(&auth_unix_all, au, au_alllink); 169 TAILQ_INSERT_TAIL(&auth_unix_all, au, 170 au_alllink); 171 sx_xunlock(&auth_unix_lock); 172 } else { 173 sx_sunlock(&auth_unix_lock); 174 } 175 return (au->au_auth); 176 } 177 } 178 179 sx_sunlock(&auth_unix_lock); 180 181 /* 182 * Allocate and set up auth handle 183 */ 184 au = NULL; 185 auth = mem_alloc(sizeof(*auth)); 186 au = mem_alloc(sizeof(*au)); 187 auth->ah_ops = &authunix_ops; 188 auth->ah_private = (caddr_t)au; 189 auth->ah_verf = au->au_shcred = _null_auth; 190 refcount_init(&au->au_refs, 1); 191 au->au_xcred = xcr; 192 au->au_shfaults = 0; 193 au->au_origcred.oa_base = NULL; 194 au->au_auth = auth; 195 196 getmicrotime(&now); 197 time = now.tv_sec; 198 199 /* 200 * Serialize the parameters into origcred 201 */ 202 xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE); 203 cru2x(cred, &xcr); 204 if (! xdr_authunix_parms(&xdrs, &time, &xcr)) 205 panic("authunix_create: failed to encode creds"); 206 au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs); 207 au->au_origcred.oa_flavor = AUTH_UNIX; 208 au->au_origcred.oa_base = mem_alloc((u_int) len); 209 memcpy(au->au_origcred.oa_base, mymem, (size_t)len); 210 211 /* 212 * set auth handle to reflect new cred. 213 */ 214 auth->ah_cred = au->au_origcred; 215 marshal_new_auth(auth); 216 217 sx_xlock(&auth_unix_lock); 218 TAILQ_FOREACH(tau, &auth_unix_cache[h], au_link) { 219 if (!memcmp(&xcr, &tau->au_xcred, sizeof(xcr))) { 220 /* 221 * We lost a race to create the AUTH that 222 * matches this cred. 223 */ 224 sx_xunlock(&auth_unix_lock); 225 AUTH_DESTROY(auth); 226 goto again; 227 } 228 } 229 230 auth_unix_count++; 231 TAILQ_INSERT_TAIL(&auth_unix_cache[h], au, au_link); 232 TAILQ_INSERT_TAIL(&auth_unix_all, au, au_alllink); 233 refcount_acquire(&au->au_refs); /* one for the cache, one for user */ 234 sx_xunlock(&auth_unix_lock); 235 236 return (auth); 237 } 238 239 /* 240 * authunix operations 241 */ 242 243 /* ARGSUSED */ 244 static void 245 authunix_nextverf(AUTH *auth) 246 { 247 /* no action necessary */ 248 } 249 250 static bool_t 251 authunix_marshal(AUTH *auth, uint32_t xid, XDR *xdrs, struct mbuf *args) 252 { 253 struct audata *au; 254 255 au = AUTH_PRIVATE(auth); 256 if (!XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos)) 257 return (FALSE); 258 259 xdrmbuf_append(xdrs, args); 260 261 return (TRUE); 262 } 263 264 static bool_t 265 authunix_validate(AUTH *auth, uint32_t xid, struct opaque_auth *verf, 266 struct mbuf **mrepp) 267 { 268 struct audata *au; 269 XDR txdrs; 270 271 if (!verf) 272 return (TRUE); 273 274 if (verf->oa_flavor == AUTH_SHORT) { 275 au = AUTH_PRIVATE(auth); 276 xdrmem_create(&txdrs, verf->oa_base, verf->oa_length, 277 XDR_DECODE); 278 279 if (au->au_shcred.oa_base != NULL) { 280 mem_free(au->au_shcred.oa_base, 281 au->au_shcred.oa_length); 282 au->au_shcred.oa_base = NULL; 283 } 284 if (xdr_opaque_auth(&txdrs, &au->au_shcred)) { 285 auth->ah_cred = au->au_shcred; 286 } else { 287 txdrs.x_op = XDR_FREE; 288 (void)xdr_opaque_auth(&txdrs, &au->au_shcred); 289 au->au_shcred.oa_base = NULL; 290 auth->ah_cred = au->au_origcred; 291 } 292 marshal_new_auth(auth); 293 } 294 295 return (TRUE); 296 } 297 298 static bool_t 299 authunix_refresh(AUTH *auth, void *dummy) 300 { 301 struct audata *au = AUTH_PRIVATE(auth); 302 struct xucred xcr; 303 uint32_t time; 304 struct timeval now; 305 XDR xdrs; 306 int stat; 307 308 if (auth->ah_cred.oa_base == au->au_origcred.oa_base) { 309 /* there is no hope. Punt */ 310 return (FALSE); 311 } 312 au->au_shfaults ++; 313 314 /* first deserialize the creds back into a struct ucred */ 315 xdrmem_create(&xdrs, au->au_origcred.oa_base, 316 au->au_origcred.oa_length, XDR_DECODE); 317 stat = xdr_authunix_parms(&xdrs, &time, &xcr); 318 if (! stat) 319 goto done; 320 321 /* update the time and serialize in place */ 322 getmicrotime(&now); 323 time = now.tv_sec; 324 xdrs.x_op = XDR_ENCODE; 325 XDR_SETPOS(&xdrs, 0); 326 327 stat = xdr_authunix_parms(&xdrs, &time, &xcr); 328 if (! stat) 329 goto done; 330 auth->ah_cred = au->au_origcred; 331 marshal_new_auth(auth); 332 done: 333 XDR_DESTROY(&xdrs); 334 return (stat); 335 } 336 337 static void 338 authunix_destroy(AUTH *auth) 339 { 340 struct audata *au; 341 342 au = AUTH_PRIVATE(auth); 343 344 if (!refcount_release(&au->au_refs)) 345 return; 346 347 mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length); 348 349 if (au->au_shcred.oa_base != NULL) 350 mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length); 351 352 mem_free(auth->ah_private, sizeof(struct audata)); 353 354 if (auth->ah_verf.oa_base != NULL) 355 mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length); 356 357 mem_free(auth, sizeof(*auth)); 358 } 359 360 /* 361 * Marshals (pre-serializes) an auth struct. 362 * sets private data, au_marshed and au_mpos 363 */ 364 static void 365 marshal_new_auth(AUTH *auth) 366 { 367 XDR xdr_stream; 368 XDR *xdrs = &xdr_stream; 369 struct audata *au; 370 371 au = AUTH_PRIVATE(auth); 372 xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE); 373 if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) || 374 (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) 375 printf("auth_none.c - Fatal marshalling problem"); 376 else 377 au->au_mpos = XDR_GETPOS(xdrs); 378 XDR_DESTROY(xdrs); 379 } 380