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.
143 #if defined(AFS_SUN5_ENV)
144 afs_setpag(struct AFS_UCRED **credpp)
145 #elif defined(AFS_OSF_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
146 afs_setpag(struct proc *p, void *args, int *retval)
153 #if defined(AFS_SGI53_ENV) && defined(MP)
154 /* This is our first chance to get the global lock. */
156 #endif /* defined(AFS_SGI53_ENV) && defined(MP) */
158 AFS_STATCNT(afs_setpag);
159 #if defined(AFS_SUN5_ENV)
160 if (!afs_suser(*credpp))
161 #elif defined(AFS_OBSD_ENV)
162 if (!afs_osi_suser(p->p_ucred))
167 while (osi_Time() - pag_epoch < pagCounter) {
168 afs_osi_Wait(1000, (struct afs_osi_WaitHandle *)0, 0);
171 #if defined(AFS_SUN5_ENV)
172 code = AddPag(genpag(), credpp);
173 #elif defined(AFS_OSF_ENV) || defined(AFS_XBSD_ENV)
174 code = AddPag(p, genpag(), &p->p_rcred);
175 #elif defined(AFS_AIX41_ENV)
178 struct ucred *credp0;
182 code = AddPag(genpag(), &credp);
183 /* If AddPag() didn't make a new cred, then free our cred ref */
184 if (credp == credp0) {
188 #elif defined(AFS_HPUX110_ENV)
190 struct ucred *credp = p_cred(u.u_procp);
191 code = AddPag(genpag(), &credp);
193 #elif defined(AFS_SGI_ENV)
196 credp = OSI_GET_CURRENT_CRED();
197 code = AddPag(genpag(), &credp);
199 #elif defined(AFS_LINUX20_ENV)
201 struct AFS_UCRED *credp = crref();
202 code = AddPag(genpag(), &credp);
205 #elif defined(AFS_DARWIN_ENV)
207 struct ucred *credp = crdup(p->p_cred->pc_ucred);
208 code = AddPag(p, genpag(), &credp);
212 code = AddPag(genpag(), &u.u_cred);
215 afs_Trace1(afs_iclSetp, CM_TRACE_SETPAG, ICL_TYPE_INT32, code);
216 #if defined(KERNEL_HAVE_UERROR)
220 #if defined(AFS_SGI53_ENV) && defined(MP)
222 #endif /* defined(AFS_SGI53_ENV) && defined(MP) */
226 #if defined(UKERNEL) && defined(AFS_WEB_ENHANCEMENTS)
229 * This function is like setpag but sets the current thread's pag id to a
230 * caller-provided value instead of calling genpag(). This implements a
231 * form of token caching since the caller can recall a particular pag value
232 * for the thread to restore tokens, rather than reauthenticating.
235 #if defined(AFS_SUN5_ENV)
236 afs_setpag_val(struct AFS_UCRED **credpp, int pagval)
237 #elif defined(AFS_OSF_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
238 afs_setpag_val(struct proc *p, void *args, int *retval, int pagval)
240 afs_setpag_val(int pagval)
245 #if defined(AFS_SGI53_ENV) && defined(MP)
246 /* This is our first chance to get the global lock. */
248 #endif /* defined(AFS_SGI53_ENV) && defined(MP) */
250 AFS_STATCNT(afs_setpag);
252 if (!afs_suser(*credpp))
257 while (osi_Time() - pag_epoch < pagCounter) {
258 afs_osi_Wait(1000, (struct afs_osi_WaitHandle *)0, 0);
261 #if defined(AFS_SUN5_ENV)
262 code = AddPag(pagval, credpp);
263 #elif defined(AFS_OSF_ENV) || defined(AFS_XBSD_ENV)
264 code = AddPag(p, pagval, &p->p_rcred);
265 #elif defined(AFS_AIX41_ENV)
268 struct ucred *credp0;
272 code = AddPag(pagval, &credp);
273 /* If AddPag() didn't make a new cred, then free our cred ref */
274 if (credp == credp0) {
278 #elif defined(AFS_HPUX110_ENV)
280 struct ucred *credp = p_cred(u.u_procp);
281 code = AddPag(pagval, &credp);
283 #elif defined(AFS_SGI_ENV)
286 credp = OSI_GET_CURRENT_CRED();
287 code = AddPag(pagval, &credp);
289 #elif defined(AFS_LINUX20_ENV)
291 struct AFS_UCRED *credp = crref();
292 code = AddPag(pagval, &credp);
295 #elif defined(AFS_DARWIN_ENV)
297 struct ucred *credp = crdup(p->p_cred->pc_ucred);
298 code = AddPag(p, pagval, &credp);
302 code = AddPag(pagval, &u.u_cred);
305 afs_Trace1(afs_iclSetp, CM_TRACE_SETPAG, ICL_TYPE_INT32, code);
306 #if defined(KERNEL_HAVE_UERROR)
310 #if defined(AFS_SGI53_ENV) && defined(MP)
312 #endif /* defined(AFS_SGI53_ENV) && defined(MP) */
320 struct AFS_UCRED *credp = u.u_cred;
321 int gidset0, gidset1;
323 gidset0 = credp->cr_groups[0];
324 gidset1 = credp->cr_groups[1];
325 pagvalue = afs_get_pag_from_groups(gidset0, gidset1);
328 #endif /* UKERNEL && AFS_WEB_ENHANCEMENTS */
331 /* Note - needs to be available on AIX, others can be static - rework this */
332 #if defined(AFS_OSF_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
334 AddPag(struct proc *p, afs_int32 aval, struct AFS_UCRED **credpp)
337 AddPag(afs_int32 aval, struct AFS_UCRED **credpp)
340 afs_int32 newpag, code;
343 #if defined(AFS_OSF_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
344 if ((code = setpag(p, credpp, aval, &newpag, 0)))
346 if ((code = setpag(credpp, aval, &newpag, 0)))
348 #if defined(KERNEL_HAVE_UERROR)
349 return (setuerror(code), code);
358 afs_InitReq(register struct vrequest *av, struct AFS_UCRED *acred)
360 AFS_STATCNT(afs_InitReq);
361 if (afs_shuttingdown)
363 av->uid = PagInCred(acred);
364 if (av->uid == NOPAG) {
365 /* Afs doesn't use the unix uid for anuthing except a handle
366 * with which to find the actual authentication tokens so I
367 * think it's ok to use the real uid to make setuid
368 * programs (without setpag) to work properly.
370 #if defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
372 av->uid = -2; /* XXX nobody... ? */
374 av->uid = acred->cr_uid; /* bsd creds don't have ruid */
376 av->uid = acred->cr_ruid; /* default when no pag is set */
386 afs_get_pag_from_groups(gid_t g0a, gid_t g1a)
390 afs_uint32 h, l, ret;
392 AFS_STATCNT(afs_get_pag_from_groups);
395 if (g0 < 0xc000 && g1 < 0xc000) {
396 l = ((g0 & 0x3fff) << 14) | (g1 & 0x3fff);
398 h = (g1 >> 14) + h + h + h;
399 ret = ((h << 28) | l);
400 #if defined(UKERNEL) && defined(AFS_WEB_ENHANCEMENTS)
403 /* Additional testing */
404 if (((ret >> 24) & 0xff) == 'A')
408 #endif /* UKERNEL && AFS_WEB_ENHANCEMENTS */
415 afs_get_groups_from_pag(afs_uint32 pag, gid_t * g0p, gid_t * g1p)
417 unsigned short g0, g1;
420 AFS_STATCNT(afs_get_groups_from_pag);
421 #if !defined(UKERNEL) || !defined(AFS_WEB_ENHANCEMENTS)
423 #endif /* UKERNEL && AFS_WEB_ENHANCEMENTS */
424 g0 = 0x3fff & (pag >> 14);
426 g0 |= ((pag >> 28) / 3) << 14;
427 g1 |= ((pag >> 28) % 3) << 14;
434 PagInCred(const struct AFS_UCRED *cred)
439 AFS_STATCNT(PagInCred);
443 #if defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
444 if (cred == NOCRED || cred == FSCRED) {
447 if (cred->cr_ngroups < 3)
449 /* gid is stored in cr_groups[0] */
450 g0 = cred->cr_groups[1];
451 g1 = cred->cr_groups[2];
453 #if defined(AFS_AIX51_ENV)
454 if (kcred_getpag(cred, PAG_AFS, &pag) < 0 || pag == 0)
457 #elif defined(AFS_AIX_ENV)
458 if (cred->cr_ngrps < 2) {
461 #elif defined(AFS_LINUX26_ENV)
462 if (cred->cr_group_info->ngroups < 2)
464 #elif defined(AFS_SGI_ENV) || defined(AFS_SUN5_ENV) || defined(AFS_DUX40_ENV) || defined(AFS_LINUX20_ENV) || defined(AFS_XBSD_ENV)
465 if (cred->cr_ngroups < 2)
468 #if defined(AFS_AIX51_ENV)
469 g0 = cred->cr_groupset.gs_union.un_groups[0];
470 g1 = cred->cr_groupset.gs_union.un_groups[1];
471 #elif defined(AFS_LINUX26_ENV)
472 g0 = GROUP_AT(cred->cr_group_info, 0);
473 g1 = GROUP_AT(cred->cr_group_info, 1);
475 g0 = cred->cr_groups[0];
476 g1 = cred->cr_groups[1];
479 pag = (afs_int32) afs_get_pag_from_groups(g0, g1);