4.3BSD - /usr/src/new/sunrpc/svc_auth_unix.c

   1: /*
   2:  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   3:  * unrestricted use provided that this legend is included on all tape
   4:  * media and as a part of the software program in whole or part.  Users
   5:  * may copy or modify Sun RPC without charge, but are not authorized
   6:  * to license or distribute it to anyone else except as part of a product or
   7:  * program developed by the user.
   8:  *
   9:  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  10:  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  11:  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  12:  *
  13:  * Sun RPC is provided with no support and without any obligation on the
  14:  * part of Sun Microsystems, Inc. to assist in its use, correction,
  15:  * modification or enhancement.
  16:  *
  17:  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  18:  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  19:  * OR ANY PART THEREOF.
  20:  *
  21:  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  22:  * or profits or other special, indirect and consequential damages, even if
  23:  * Sun has been advised of the possibility of such damages.
  24:  *
  25:  * Sun Microsystems, Inc.
  26:  * 2550 Garcia Avenue
  27:  * Mountain View, California  94043
  28:  */
  29: #ifndef lint
  30: static char sccsid[] = "@(#)svc_auth_unix.c 1.4 85/03/14 Copyr 1984 Sun Micro";
  31: #endif
  32: 
  33: /*
  34:  * svc_auth_unix.c
  35:  * Handles UNIX flavor authentication parameters on the service side of rpc.
  36:  * There are two svc auth implementations here: AUTH_UNIX and AUTH_SHORT.
  37:  * _svcauth_unix does full blown unix style uid,gid+gids auth,
  38:  * _svcauth_short uses a shorthand auth to index into a cache of longhand auths.
  39:  *
  40:  * Copyright (C) 1984, Sun Microsystems, Inc.
  41:  */
  42: 
  43: #include <stdio.h>
  44: #include "types.h"
  45: #include <sys/time.h>
  46: #include <netinet/in.h>
  47: #include "xdr.h"
  48: #include "auth.h"
  49: #include "clnt.h"
  50: #include "rpc_msg.h"
  51: #include "svc.h"
  52: #include "auth_unix.h"
  53: #include "svc_auth.h"
  54: char *mem_alloc();
  55: 
  56: #define SHORT_VERF_SIZE (3 * BYTES_PER_XDR_UNIT)
  57: #define CACHE_SIZE 16
  58: 
  59: static struct cache_entry {
  60:     u_long      sh;     /* short hand value */
  61: #define SHORT_CRED_SIZE (sizeof (u_long))
  62:     short       cred_len;   /* byte length of opaque credential */
  63:     caddr_t     cred_base;  /* the opaque credential body */
  64:     struct authunix_parms aup;  /* cooked, deserialized credentials */
  65: } cache[CACHE_SIZE];
  66: 
  67: static short cacheindex[CACHE_SIZE];
  68: 
  69: /*
  70:  * Cache handling macros
  71:  */
  72: #define valid_aup(aup) (TRUE)
  73: #define nexti(i)  ((i == CACHE_SIZE-1) ? 0 : i+1)
  74: #define previ(i)  ((i == 0) ? CACHE_SIZE-1 : i-1)
  75: #define cache_hit(c, d) \
  76:    ( hits++, d=cnt-c, depth += d, maxdepth = (d > maxdepth) ? d: maxdepth )
  77: 
  78: /*
  79:  * Cache handling routines
  80:  */
  81: static short    find_short_hand();
  82: static short    find_long_hand();
  83: 
  84: /*
  85:  * Cache variables
  86:  */
  87: static short head, maxdepth;    /* values from 0 to CACHE_SIZE-1, inclusive */
  88: static short cnt;       /*  values from 0 to CACHE_SIZE, inclusive */
  89: static u_long additions, deletions, queries, hits, depth;
  90: static struct timeval last_time;
  91: static inited = 0;      /* stupid kludge to be sure init gets called */
  92: 
  93: 
  94: /*
  95:  * Unix longhand authenticator
  96:  */
  97: enum auth_stat
  98: _svcauth_unix(rqst, msg)
  99:     register struct svc_req *rqst;
 100:     register struct rpc_msg *msg;
 101: {
 102:     register short i = -1;
 103:     register int len = msg->rm_call.cb_cred.oa_length;
 104:     register caddr_t base = msg->rm_call.cb_cred.oa_base;
 105:     register enum auth_stat stat = AUTH_OK;
 106:     XDR xdrs;
 107:     struct authunix_parms aup;
 108:     struct opaque_auth short_cred;
 109: 
 110:     if (!inited) {
 111:         svcauth_unix_init();
 112:     }
 113:     while ((i = find_long_hand(base, len)) < 0) {
 114:         /* deserialize credentials */
 115:         aup.aup_machname = NULL;
 116:         aup.aup_gids = (int *)NULL;
 117:         xdrmem_create(&xdrs, base, (u_int)len, XDR_DECODE);
 118:         if (! (xdr_authunix_parms(&xdrs, &aup) && valid_aup(&aup))) {
 119:             xdrs.x_op = XDR_FREE;
 120:             (void)xdr_authunix_parms(&xdrs, &aup);
 121:             stat = AUTH_BADCRED;
 122:             goto done;
 123:         }
 124:         /* now make a new cache entry for this credential */
 125:         cache_new_user(base, len, &aup);
 126:     }
 127:     rqst->rq_clntcred = (caddr_t)&(cache[i].aup);
 128:     /* now build a verifier that suggests using the short hand credential */
 129:     short_cred.oa_flavor = AUTH_SHORT;
 130:     short_cred.oa_length = SHORT_CRED_SIZE;
 131:     short_cred.oa_base = (caddr_t)&(cache[i].sh);
 132:     /* the short hand cred get serialized into a verifier */
 133:     xdrmem_create(&xdrs, rqst->rq_xprt->xp_verf.oa_base,
 134:         SHORT_VERF_SIZE, XDR_ENCODE);
 135:     if (! xdr_opaque_auth(&xdrs, &short_cred)) {
 136:         stat = AUTH_BADCRED;
 137:         goto done;
 138:     }
 139:     rqst->rq_xprt->xp_verf.oa_length = XDR_GETPOS(&xdrs);
 140:     rqst->rq_xprt->xp_verf.oa_flavor = AUTH_SHORT;
 141: done:
 142:     XDR_DESTROY(&xdrs);
 143:     return (stat);
 144: }
 145: 
 146: 
 147: /*
 148:  * Shorthand unix authenticator
 149:  * Looks up longhand in a cache.
 150:  */
 151: enum auth_stat
 152: _svcauth_short(rqst, msg)
 153:     struct svc_req *rqst;
 154:     struct rpc_msg *msg;
 155: {
 156:     short i;
 157: 
 158:     if (!inited) {
 159:         svcauth_unix_init();
 160:     }
 161:     if (msg->rm_call.cb_cred.oa_length != SHORT_CRED_SIZE)
 162:         return (AUTH_BADCRED);
 163:     if ((i = find_short_hand(*(u_long *)msg->rm_call.cb_cred.oa_base)) < 0)
 164:         return (AUTH_REJECTEDCRED);
 165:     rqst->rq_clntcred = (caddr_t)&(cache[i].aup);
 166:     return (AUTH_OK);
 167: }
 168: 
 169: 
 170: /*
 171:  * returns cache index or -1 if sh not in the cache
 172:  */
 173: static short
 174: find_short_hand(sh)
 175:     register u_long sh;  /* short hand value */
 176: {
 177:     /* declared in order of importance */
 178:     register short entry, i, c, p;
 179: 
 180:     queries++;
 181:     for (c = cnt, i = head; c > 0; --c, i = nexti(i)) {
 182: 
 183:         entry = cacheindex[i];
 184:         if (sh == cache[entry].sh) {
 185:             /* cache hit! Now buble swap i up one notch */
 186:             cache_hit(c, p);  /* used for accounting only */
 187:             if (i != head) {
 188:                 /* c acts as the temporary variable */
 189:                 p = previ(i);
 190:                 c = cacheindex[p];
 191:                 cacheindex[p] = entry; /* gets cacheindex[i] */
 192:                 cacheindex[i] = c;
 193:             }
 194:             return (entry);
 195:         }  /* end of successful cache hit */
 196:     }
 197:     return (-1);
 198: }
 199: 
 200: /*
 201:  * returns cache index or -1 if cred not in the cache
 202:  */
 203: static short
 204: find_long_hand(cred_base, len)
 205:     register caddr_t cred_base;
 206:     register int len;
 207: {
 208:     /* declared in order of importance */
 209:     register short entry, i, c, p;
 210: 
 211:     queries++;
 212:     for (c = cnt, i = head; c > 0; --c, i = nexti(i)) {
 213: 
 214:         entry = cacheindex[i];
 215:         if ((cache[entry].cred_len == len) &&
 216:             (bcmp(cache[entry].cred_base, cred_base, len) == 0)) {
 217:             /* cache hit! Now buble swap i up one notch */
 218:             cache_hit(c, p);  /* used for accounting only */
 219:             if (i != head) {
 220:                 /* c acts as the temporary variable */
 221:                 p = previ(i);
 222:                 c = cacheindex[p];
 223:                 cacheindex[p] = entry; /* gets cacheindex[i] */
 224:                 cacheindex[i] = c;
 225:             }
 226:         return (entry);
 227:         }  /* end of successful cache hit */
 228:     }
 229:     return (-1);
 230: }
 231: 
 232: /*
 233:  * Place a new entry at the HEAD of the cache.  This means moving the
 234:  * heap index back one and possibly flushing the oldest entry from the cache.
 235:  */
 236: static
 237: cache_new_user(base, len, aup)
 238:     caddr_t base;
 239:     int len;
 240:     struct authunix_parms *aup;
 241: {
 242:     register short entry;
 243:     struct timeval now;
 244: 
 245:     head = previ(head);
 246:     entry = cacheindex[head];
 247:     if (cnt == CACHE_SIZE) { /* full cache, delete lru entry */
 248:         XDR xdrs;
 249: 
 250:         xdrs.x_op = XDR_FREE;
 251:         deletions++;
 252:         if (cache[entry].cred_base != NULL) {
 253:             mem_free(cache[entry].cred_base,
 254:                 cache[entry].cred_len);
 255:             cache[entry].cred_base = NULL;
 256:         }
 257:         (void)xdr_authunix_parms(&xdrs, &cache[entry].aup);
 258:     } else {
 259:         cnt++;
 260:     }
 261:     /* now add current entry, raw cred must be copied */
 262:     additions++;
 263:     cache[entry].aup = *aup;
 264:     cache[entry].cred_len = len;
 265:     if ((cache[entry].cred_base = (char *)mem_alloc(len)) == NULL) {
 266:         fprintf(stderr, "cache_new_user: out of memory\n");
 267:         additions--;
 268:         return;
 269:     }
 270:     bcopy(base, cache[entry].cred_base, (u_int)len);
 271:     /* finally compute a new, unique short hand value */
 272:     cache[entry].sh = ++ last_time.tv_sec;
 273:     /* don't let real time get ahead of last_time */
 274:     while (TRUE) {
 275:         (void)gettimeofday(&now, (struct timezone *)0);
 276:         if (((long int)now.tv_sec - (long int)last_time.tv_sec) > 0)
 277:             break;
 278:         sleep(1);
 279:     }
 280: }
 281: 
 282: /*
 283:  * Initialize the shorthand cache.
 284:  * Must be called before unix auth can be used!
 285:  */
 286: static svcauth_unix_init()
 287: {
 288:     register short i;
 289: 
 290:     inited++;
 291:     (void)gettimeofday(&last_time, (struct timezone *)0);
 292:     for (i = 0; i < CACHE_SIZE; ++i) {
 293:         cacheindex[i] = i;
 294:     }
 295: }

Defined functions

Defined variables

Defined struct's

Defined macros