2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
17 * afs_get_pag_from_groups
18 * afs_get_groups_from_pag
22 #include <afsconfig.h>
23 #include "afs/param.h"
28 #include "afs/sysincludes.h" /* Standard vendor system headers */
29 #include "afsincludes.h" /* Afs-based standard headers */
30 #include "afs/afs_stats.h" /* statistics */
31 #include "afs/afs_cbqueue.h"
32 #include "afs/nfsclient.h"
33 #include "afs/afs_osidnlc.h"
36 /* Imported variables */
37 extern int afs_shuttingdown;
39 /* Exported variables */
41 #if defined(UKERNEL) && defined(AFS_WEB_ENHANCEMENTS)
42 afs_uint32 pagCounter = 1;
44 afs_uint32 pagCounter = 0;
45 #endif /* UKERNEL && AFS_WEB_ENHANCEMENTS */
50 * Pags are implemented as follows: the set of groups whose long
51 * representation is '41XXXXXX' hex are used to represent the pags.
52 * Being a member of such a group means you are authenticated as pag
53 * XXXXXX (0x41 == 'A', for Andrew). You are never authenticated as
54 * multiple pags at once.
56 * The function afs_InitReq takes a credential field and formats the
57 * corresponding venus request structure. The uid field in the
58 * vrequest structure is set to the *pag* you are authenticated as, or
59 * the uid, if you aren't authenticated with a pag.
61 * The basic motivation behind pags is this: just because your unix
62 * uid is N doesn't mean that you should have the same privileges as
63 * anyone logged in on the machine as user N, since this would enable
64 * the superuser on the machine to sneak in and make use of anyone's
65 * authentication info, even that which is only accidentally left
66 * behind when someone leaves a public workstation.
68 * AFS doesn't use the unix uid for anything except
69 * a handle with which to find the actual authentication tokens
70 * anyway, so the pag is an alternative handle which is somewhat more
71 * secure (although of course not absolutely secure).
73 #if !defined(UKERNEL) || !defined(AFS_WEB_ENHANCEMENTS)
78 #ifdef AFS_LINUX20_ENV
79 /* Ensure unique PAG's (mod 200 days) when reloading the client. */
80 return (('A' << 24) + ((pag_epoch + pagCounter++) & 0xffffff));
81 #else /* AFS_LINUX20_ENV */
82 return (('A' << 24) + (pagCounter++ & 0xffffff));
83 #endif /* AFS_LINUX20_ENV */
90 #ifdef AFS_LINUX20_ENV
91 /* Ensure unique PAG's (mod 200 days) when reloading the client. */
92 return (('A' << 24) + ((pag_epoch + pagCounter) & 0xffffff));
94 return (('A' << 24) + (pagCounter & 0xffffff));
100 /* Web enhancement: we don't need to restrict pags to 41XXXXXX since
101 * we are not sharing the space with anyone. So we use the full 32 bits. */
107 #ifdef AFS_LINUX20_ENV
108 return (pag_epoch + pagCounter++);
110 return (pagCounter++);
111 #endif /* AFS_LINUX20_ENV */
118 #ifdef AFS_LINUX20_ENV
119 /* Ensure unique PAG's (mod 200 days) when reloading the client. */
120 return (pag_epoch + pagCounter);
125 #endif /* UKERNEL && AFS_WEB_ENHANCEMENTS */
127 /* used to require 10 seconds between each setpag to guarantee that
128 * PAGs never wrap - which would be a security hole. If we presume
129 * that in ordinary operation, the average rate of PAG allocation
130 * will not exceed one per second, the 24 bits provided will be
131 * sufficient for ~200 days. Unfortunately, if we merely assume that,
132 * there will be an opportunity for attack. So we must enforce it.
133 * If we need to increase the average rate of PAG allocation, we
134 * should increase the number of bits in a PAG, and/or reduce our
135 * window in which we guarantee that the PAG counter won't wrap.
136 * By permitting an average of one new PAG per second, new PAGs can
137 * be allocated VERY frequently over a short period relative to total uptime.
138 * Of course, there's only an issue here if one user stays logged (and re-
139 * activates tokens repeatedly) for that entire period.
142 static int afs_pag_sleepcnt = 0;
145 afs_pag_sleep(struct AFS_UCRED **acred)
149 if (!afs_suser(acred)) {
150 if(osi_Time() - pag_epoch < pagCounter) {
159 afs_pag_wait(struct AFS_UCRED **acred)
161 if (afs_pag_sleep(acred)) {
162 if (!afs_pag_sleepcnt) {
163 printf("%s() PAG throttling triggered, pid %d... sleeping. sleepcnt %d\n",
164 "afs_pag_wait", osi_getpid(), afs_pag_sleepcnt);
170 /* XXX spins on EINTR */
171 afs_osi_Wait(1000, (struct afs_osi_WaitHandle *)0, 0);
172 } while (afs_pag_sleep(acred));
181 #if defined(AFS_SUN5_ENV)
182 afs_setpag(struct AFS_UCRED **credpp)
183 #elif defined(AFS_OSF_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
184 afs_setpag(struct proc *p, void *args, int *retval)
190 #if defined(AFS_SUN5_ENV)
191 struct AFS_UCRED **acred = *credpp;
192 #elif defined(AFS_OBSD_ENV)
193 struct AFS_UCRED **acred = &p->p_ucred;
195 struct AFS_UCRED **acred = NULL;
200 #if defined(AFS_SGI53_ENV) && defined(MP)
201 /* This is our first chance to get the global lock. */
203 #endif /* defined(AFS_SGI53_ENV) && defined(MP) */
205 AFS_STATCNT(afs_setpag);
210 #if defined(AFS_SUN5_ENV)
211 code = AddPag(genpag(), credpp);
212 #elif defined(AFS_OSF_ENV) || defined(AFS_XBSD_ENV)
213 code = AddPag(p, genpag(), &p->p_rcred);
214 #elif defined(AFS_AIX41_ENV)
217 struct ucred *credp0;
221 code = AddPag(genpag(), &credp);
222 /* If AddPag() didn't make a new cred, then free our cred ref */
223 if (credp == credp0) {
227 #elif defined(AFS_HPUX110_ENV)
229 struct ucred *credp = p_cred(u.u_procp);
230 code = AddPag(genpag(), &credp);
232 #elif defined(AFS_SGI_ENV)
235 credp = OSI_GET_CURRENT_CRED();
236 code = AddPag(genpag(), &credp);
238 #elif defined(AFS_LINUX20_ENV)
240 struct AFS_UCRED *credp = crref();
241 code = AddPag(genpag(), &credp);
244 #elif defined(AFS_DARWIN80_ENV)
246 struct ucred *credp = kauth_cred_proc_ref(p);
247 code = AddPag(p, genpag(), &credp);
248 kauth_cred_rele(credp);
250 #elif defined(AFS_DARWIN_ENV)
252 struct ucred *credp = crdup(p->p_cred->pc_ucred);
253 code = AddPag(p, genpag(), &credp);
257 code = AddPag(genpag(), &u.u_cred);
260 afs_Trace1(afs_iclSetp, CM_TRACE_SETPAG, ICL_TYPE_INT32, code);
262 #if defined(KERNEL_HAVE_UERROR)
267 #if defined(AFS_SGI53_ENV) && defined(MP)
269 #endif /* defined(AFS_SGI53_ENV) && defined(MP) */
274 #if defined(UKERNEL) && defined(AFS_WEB_ENHANCEMENTS)
277 * This function is like setpag but sets the current thread's pag id to a
278 * caller-provided value instead of calling genpag(). This implements a
279 * form of token caching since the caller can recall a particular pag value
280 * for the thread to restore tokens, rather than reauthenticating.
283 #if defined(AFS_SUN5_ENV)
284 afs_setpag_val(struct AFS_UCRED **credpp, int pagval)
285 #elif defined(AFS_OSF_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
286 afs_setpag_val(struct proc *p, void *args, int *retval, int pagval)
288 afs_setpag_val(int pagval)
292 #if defined(AFS_SUN5_ENV)
293 struct AFS_UCRED **acred = *credp;
294 #elif defined(AFS_OBSD_ENV)
295 struct AFS_UCRED **acred = &p->p_ucred;
297 struct AFS_UCRED **acred = NULL;
302 #if defined(AFS_SGI53_ENV) && defined(MP)
303 /* This is our first chance to get the global lock. */
305 #endif /* defined(AFS_SGI53_ENV) && defined(MP) */
307 AFS_STATCNT(afs_setpag);
311 #if defined(AFS_SUN5_ENV)
312 code = AddPag(pagval, credpp);
313 #elif defined(AFS_OSF_ENV) || defined(AFS_XBSD_ENV)
314 code = AddPag(p, pagval, &p->p_rcred);
315 #elif defined(AFS_AIX41_ENV)
318 struct ucred *credp0;
322 code = AddPag(pagval, &credp);
323 /* If AddPag() didn't make a new cred, then free our cred ref */
324 if (credp == credp0) {
328 #elif defined(AFS_HPUX110_ENV)
330 struct ucred *credp = p_cred(u.u_procp);
331 code = AddPag(pagval, &credp);
333 #elif defined(AFS_SGI_ENV)
336 credp = OSI_GET_CURRENT_CRED();
337 code = AddPag(pagval, &credp);
339 #elif defined(AFS_LINUX20_ENV)
341 struct AFS_UCRED *credp = crref();
342 code = AddPag(pagval, &credp);
345 #elif defined(AFS_DARWIN_ENV)
347 struct ucred *credp = crdup(p->p_cred->pc_ucred);
348 code = AddPag(p, pagval, &credp);
352 code = AddPag(pagval, &u.u_cred);
355 afs_Trace1(afs_iclSetp, CM_TRACE_SETPAG, ICL_TYPE_INT32, code);
356 #if defined(KERNEL_HAVE_UERROR)
360 #if defined(AFS_SGI53_ENV) && defined(MP)
362 #endif /* defined(AFS_SGI53_ENV) && defined(MP) */
370 struct AFS_UCRED *credp = u.u_cred;
371 gid_t gidset0, gidset1;
372 #ifdef AFS_SUN510_ENV
375 gids = crgetgroups(*credp);
380 gidset0 = credp->cr_groups[0];
381 gidset1 = credp->cr_groups[1];
383 pagvalue = afs_get_pag_from_groups(gidset0, gidset1);
386 #endif /* UKERNEL && AFS_WEB_ENHANCEMENTS */
389 /* Note - needs to be available on AIX, others can be static - rework this */
390 #if defined(AFS_OSF_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
392 AddPag(struct proc *p, afs_int32 aval, struct AFS_UCRED **credpp)
395 AddPag(afs_int32 aval, struct AFS_UCRED **credpp)
398 afs_int32 newpag, code;
401 #if defined(AFS_OSF_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
402 if ((code = setpag(p, credpp, aval, &newpag, 0)))
404 if ((code = setpag(credpp, aval, &newpag, 0)))
406 #if defined(KERNEL_HAVE_UERROR)
407 return (setuerror(code), code);
416 afs_InitReq(register struct vrequest *av, struct AFS_UCRED *acred)
420 AFS_STATCNT(afs_InitReq);
421 memset(av, 0, sizeof(*av));
422 if (afs_shuttingdown)
425 #ifdef AFS_LINUX26_ENV
426 if (osi_linux_nfs_initreq(av, acred, &code))
430 av->uid = PagInCred(acred);
431 if (av->uid == NOPAG) {
432 /* Afs doesn't use the unix uid for anuthing except a handle
433 * with which to find the actual authentication tokens so I
434 * think it's ok to use the real uid to make setuid
435 * programs (without setpag) to work properly.
437 #if defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
439 av->uid = -2; /* XXX nobody... ? */
441 av->uid = acred->cr_uid; /* bsd creds don't have ruid */
442 #elif defined(AFS_SUN510_ENV)
443 av->uid = crgetruid(acred);
445 av->uid = acred->cr_ruid; /* default when no pag is set */
455 afs_get_pag_from_groups(gid_t g0a, gid_t g1a)
459 afs_uint32 h, l, ret;
461 AFS_STATCNT(afs_get_pag_from_groups);
464 if (g0 < 0xc000 && g1 < 0xc000) {
465 l = ((g0 & 0x3fff) << 14) | (g1 & 0x3fff);
467 h = (g1 >> 14) + h + h + h;
468 ret = ((h << 28) | l);
469 #if defined(UKERNEL) && defined(AFS_WEB_ENHANCEMENTS)
472 /* Additional testing */
473 if (((ret >> 24) & 0xff) == 'A')
475 #endif /* UKERNEL && AFS_WEB_ENHANCEMENTS */
482 afs_get_groups_from_pag(afs_uint32 pag, gid_t * g0p, gid_t * g1p)
484 unsigned short g0, g1;
487 AFS_STATCNT(afs_get_groups_from_pag);
488 #if !defined(UKERNEL) || !defined(AFS_WEB_ENHANCEMENTS)
490 #endif /* UKERNEL && AFS_WEB_ENHANCEMENTS */
491 g0 = 0x3fff & (pag >> 14);
493 g0 |= ((pag >> 28) / 3) << 14;
494 g1 |= ((pag >> 28) % 3) << 14;
501 PagInCred(const struct AFS_UCRED *cred)
505 #if defined(AFS_SUN510_ENV)
510 AFS_STATCNT(PagInCred);
511 if (cred == NULL || cred == afs_osi_credp) {
514 #if defined(AFS_SUN510_ENV)
515 gids = crgetgroups(cred);
516 ngroups = crgetngroups(cred);
518 #if defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
519 if (cred == NOCRED || cred == FSCRED) {
522 if (cred->cr_ngroups < 3)
524 /* gid is stored in cr_groups[0] */
525 g0 = cred->cr_groups[1];
526 g1 = cred->cr_groups[2];
528 #if defined(AFS_AIX51_ENV)
529 if (kcred_getpag(cred, PAG_AFS, &pag) < 0 || pag == 0)
532 #elif defined(AFS_AIX_ENV)
533 if (cred->cr_ngrps < 2) {
536 #elif defined(AFS_LINUX26_ENV)
537 if (cred->cr_group_info->ngroups < 2) {
541 #elif defined(AFS_SGI_ENV) || defined(AFS_SUN5_ENV) || defined(AFS_DUX40_ENV) || defined(AFS_LINUX20_ENV) || defined(AFS_XBSD_ENV)
542 #if defined(AFS_SUN510_ENV)
545 if (cred->cr_ngroups < 2) {
551 #if defined(AFS_AIX51_ENV)
552 g0 = cred->cr_groupset.gs_union.un_groups[0];
553 g1 = cred->cr_groupset.gs_union.un_groups[1];
554 #elif defined(AFS_LINUX26_ENV)
555 g0 = GROUP_AT(cred->cr_group_info, 0);
556 g1 = GROUP_AT(cred->cr_group_info, 1);
557 #elif defined(AFS_SUN510_ENV)
561 g0 = cred->cr_groups[0];
562 g1 = cred->cr_groups[1];
565 pag = (afs_int32) afs_get_pag_from_groups(g0, g1);
567 #if defined(AFS_LINUX26_ENV) && defined(LINUX_KEYRING_SUPPORT)
570 afs_uint32 pag, newpag;
572 key = request_key(&key_type_afs_pag, "_pag", NULL);
574 if (key_validate(key) == 0 && key->uid == 0) { /* also verify in the session keyring? */
576 pag = (afs_uint32) key->payload.value;
577 if (((pag >> 24) & 0xff) == 'A')
578 __setpag(&cred, pag, &newpag, 0);