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 66 #include <rpc/rpc_com.h> 67 68 /* auth_unix.c */ 69 static void authunix_nextverf (AUTH *); 70 static bool_t authunix_marshal (AUTH *, XDR *); 71 static bool_t authunix_validate (AUTH *, struct opaque_auth *); 72 static bool_t authunix_refresh (AUTH *, void *); 73 static void authunix_destroy (AUTH *); 74 static void marshal_new_auth (AUTH *); 75 76 static struct auth_ops authunix_ops = { 77 .ah_nextverf = authunix_nextverf, 78 .ah_marshal = authunix_marshal, 79 .ah_validate = authunix_validate, 80 .ah_refresh = authunix_refresh, 81 .ah_destroy = authunix_destroy 82 }; 83 84 /* 85 * This struct is pointed to by the ah_private field of an auth_handle. 86 */ 87 struct audata { 88 TAILQ_ENTRY(audata) au_link; 89 TAILQ_ENTRY(audata) au_alllink; 90 volatile u_int au_refs; 91 struct xucred au_xcred; 92 struct opaque_auth au_origcred; /* original credentials */ 93 struct opaque_auth au_shcred; /* short hand cred */ 94 u_long au_shfaults; /* short hand cache faults */ 95 char au_marshed[MAX_AUTH_BYTES]; 96 u_int au_mpos; /* xdr pos at end of marshed */ 97 AUTH *au_auth; /* link back to AUTH */ 98 }; 99 TAILQ_HEAD(audata_list, audata); 100 #define AUTH_PRIVATE(auth) ((struct audata *)auth->ah_private) 101 102 #define AUTH_UNIX_HASH_SIZE 16 103 #define AUTH_UNIX_MAX 256 104 static struct audata_list auth_unix_cache[AUTH_UNIX_HASH_SIZE]; 105 static struct audata_list auth_unix_all; 106 static struct sx auth_unix_lock; 107 static int auth_unix_count; 108 109 static void 110 authunix_init(void *dummy) 111 { 112 int i; 113 114 for (i = 0; i < AUTH_UNIX_HASH_SIZE; i++) 115 TAILQ_INIT(&auth_unix_cache[i]); 116 TAILQ_INIT(&auth_unix_all); 117 sx_init(&auth_unix_lock, "auth_unix_lock"); 118 } 119 SYSINIT(authunix_init, SI_SUB_KMEM, SI_ORDER_ANY, authunix_init, NULL); 120 121 /* 122 * Create a unix style authenticator. 123 * Returns an auth handle with the given stuff in it. 124 */ 125 AUTH * 126 authunix_create(struct ucred *cred) 127 { 128 uint32_t h, th; 129 struct xucred xcr; 130 char mymem[MAX_AUTH_BYTES]; 131 XDR xdrs; 132 AUTH *auth; 133 struct audata *au, *tau; 134 struct timeval now; 135 uint32_t time; 136 int len; 137 138 if (auth_unix_count > AUTH_UNIX_MAX) { 139 while (auth_unix_count > AUTH_UNIX_MAX) { 140 sx_xlock(&auth_unix_lock); 141 tau = TAILQ_FIRST(&auth_unix_all); 142 th = HASHSTEP(HASHINIT, tau->au_xcred.cr_uid) 143 % AUTH_UNIX_HASH_SIZE; 144 TAILQ_REMOVE(&auth_unix_cache[th], tau, au_link); 145 TAILQ_REMOVE(&auth_unix_all, tau, au_alllink); 146 auth_unix_count--; 147 sx_xunlock(&auth_unix_lock); 148 AUTH_DESTROY(tau->au_auth); 149 } 150 } 151 152 /* 153 * Hash the uid to see if we already have an AUTH with this cred. 154 */ 155 h = HASHSTEP(HASHINIT, cred->cr_uid) % AUTH_UNIX_HASH_SIZE; 156 cru2x(cred, &xcr); 157 again: 158 sx_slock(&auth_unix_lock); 159 TAILQ_FOREACH(au, &auth_unix_cache[h], au_link) { 160 if (!memcmp(&xcr, &au->au_xcred, sizeof(xcr))) { 161 refcount_acquire(&au->au_refs); 162 if (sx_try_upgrade(&auth_unix_lock)) { 163 /* 164 * Keep auth_unix_all LRU sorted. 165 */ 166 TAILQ_REMOVE(&auth_unix_all, au, au_alllink); 167 TAILQ_INSERT_TAIL(&auth_unix_all, au, 168 au_alllink); 169 sx_xunlock(&auth_unix_lock); 170 } else { 171 sx_sunlock(&auth_unix_lock); 172 } 173 return (au->au_auth); 174 } 175 } 176 177 sx_sunlock(&auth_unix_lock); 178 179 /* 180 * Allocate and set up auth handle 181 */ 182 au = NULL; 183 auth = mem_alloc(sizeof(*auth)); 184 au = mem_alloc(sizeof(*au)); 185 auth->ah_ops = &authunix_ops; 186 auth->ah_private = (caddr_t)au; 187 auth->ah_verf = au->au_shcred = _null_auth; 188 refcount_init(&au->au_refs, 1); 189 au->au_xcred = xcr; 190 au->au_shfaults = 0; 191 au->au_origcred.oa_base = NULL; 192 au->au_auth = auth; 193 194 getmicrotime(&now); 195 time = now.tv_sec; 196 197 /* 198 * Serialize the parameters into origcred 199 */ 200 xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE); 201 cru2x(cred, &xcr); 202 if (! xdr_authunix_parms(&xdrs, &time, &xcr)) 203 panic("authunix_create: failed to encode creds"); 204 au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs); 205 au->au_origcred.oa_flavor = AUTH_UNIX; 206 au->au_origcred.oa_base = mem_alloc((u_int) len); 207 memcpy(au->au_origcred.oa_base, mymem, (size_t)len); 208 209 /* 210 * set auth handle to reflect new cred. 211 */ 212 auth->ah_cred = au->au_origcred; 213 marshal_new_auth(auth); 214 215 sx_xlock(&auth_unix_lock); 216 TAILQ_FOREACH(tau, &auth_unix_cache[h], au_link) { 217 if (!memcmp(&xcr, &tau->au_xcred, sizeof(xcr))) { 218 /* 219 * We lost a race to create the AUTH that 220 * matches this cred. 221 */ 222 sx_xunlock(&auth_unix_lock); 223 AUTH_DESTROY(auth); 224 goto again; 225 } 226 } 227 228 auth_unix_count++; 229 TAILQ_INSERT_TAIL(&auth_unix_cache[h], au, au_link); 230 TAILQ_INSERT_TAIL(&auth_unix_all, au, au_alllink); 231 refcount_acquire(&au->au_refs); /* one for the cache, one for user */ 232 sx_xunlock(&auth_unix_lock); 233 234 return (auth); 235 } 236 237 /* 238 * authunix operations 239 */ 240 241 /* ARGSUSED */ 242 static void 243 authunix_nextverf(AUTH *auth) 244 { 245 /* no action necessary */ 246 } 247 248 static bool_t 249 authunix_marshal(AUTH *auth, XDR *xdrs) 250 { 251 struct audata *au; 252 253 au = AUTH_PRIVATE(auth); 254 return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos)); 255 } 256 257 static bool_t 258 authunix_validate(AUTH *auth, struct opaque_auth *verf) 259 { 260 struct audata *au; 261 XDR xdrs; 262 263 if (verf->oa_flavor == AUTH_SHORT) { 264 au = AUTH_PRIVATE(auth); 265 xdrmem_create(&xdrs, verf->oa_base, verf->oa_length, 266 XDR_DECODE); 267 268 if (au->au_shcred.oa_base != NULL) { 269 mem_free(au->au_shcred.oa_base, 270 au->au_shcred.oa_length); 271 au->au_shcred.oa_base = NULL; 272 } 273 if (xdr_opaque_auth(&xdrs, &au->au_shcred)) { 274 auth->ah_cred = au->au_shcred; 275 } else { 276 xdrs.x_op = XDR_FREE; 277 (void)xdr_opaque_auth(&xdrs, &au->au_shcred); 278 au->au_shcred.oa_base = NULL; 279 auth->ah_cred = au->au_origcred; 280 } 281 marshal_new_auth(auth); 282 } 283 return (TRUE); 284 } 285 286 static bool_t 287 authunix_refresh(AUTH *auth, void *dummy) 288 { 289 struct audata *au = AUTH_PRIVATE(auth); 290 struct xucred xcr; 291 uint32_t time; 292 struct timeval now; 293 XDR xdrs; 294 int stat; 295 296 if (auth->ah_cred.oa_base == au->au_origcred.oa_base) { 297 /* there is no hope. Punt */ 298 return (FALSE); 299 } 300 au->au_shfaults ++; 301 302 /* first deserialize the creds back into a struct ucred */ 303 xdrmem_create(&xdrs, au->au_origcred.oa_base, 304 au->au_origcred.oa_length, XDR_DECODE); 305 stat = xdr_authunix_parms(&xdrs, &time, &xcr); 306 if (! stat) 307 goto done; 308 309 /* update the time and serialize in place */ 310 getmicrotime(&now); 311 time = now.tv_sec; 312 xdrs.x_op = XDR_ENCODE; 313 XDR_SETPOS(&xdrs, 0); 314 315 stat = xdr_authunix_parms(&xdrs, &time, &xcr); 316 if (! stat) 317 goto done; 318 auth->ah_cred = au->au_origcred; 319 marshal_new_auth(auth); 320 done: 321 XDR_DESTROY(&xdrs); 322 return (stat); 323 } 324 325 static void 326 authunix_destroy(AUTH *auth) 327 { 328 struct audata *au; 329 330 au = AUTH_PRIVATE(auth); 331 332 if (!refcount_release(&au->au_refs)) 333 return; 334 335 mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length); 336 337 if (au->au_shcred.oa_base != NULL) 338 mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length); 339 340 mem_free(auth->ah_private, sizeof(struct audata)); 341 342 if (auth->ah_verf.oa_base != NULL) 343 mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length); 344 345 mem_free(auth, sizeof(*auth)); 346 } 347 348 /* 349 * Marshals (pre-serializes) an auth struct. 350 * sets private data, au_marshed and au_mpos 351 */ 352 static void 353 marshal_new_auth(AUTH *auth) 354 { 355 XDR xdr_stream; 356 XDR *xdrs = &xdr_stream; 357 struct audata *au; 358 359 au = AUTH_PRIVATE(auth); 360 xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE); 361 if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) || 362 (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) 363 printf("auth_none.c - Fatal marshalling problem"); 364 else 365 au->au_mpos = XDR_GETPOS(xdrs); 366 XDR_DESTROY(xdrs); 367 } 368