4 * Copyright (C) 2003 Paul Jakma.
5 * Copyright (C) 2005 Sun Microsystems, Inc.
7 * This file is part of GNU Zebra.
9 * GNU Zebra is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2, or (at your option) any
14 * GNU Zebra is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with GNU Zebra; see the file COPYING. If not, write to the Free
21 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
29 #ifdef HAVE_CAPABILITIES
30 /* sort out some generic internal types for:
32 * privilege values (cap_value_t, priv_t) -> pvalue_t
33 * privilege set (..., priv_set_t) -> pset_t
34 * privilege working storage (cap_t, ...) -> pstorage_t
36 * values we think of as numeric (they're ints really, but we dont know)
37 * sets are mostly opaque, to hold a set of privileges, related in some way.
38 * storage binds together a set of sets we're interested in.
39 * (in reality: cap_value_t and priv_t are ints)
42 /* Linux doesn't have a 'set' type: a set of related privileges */
47 typedef cap_value_t pvalue_t
;
48 typedef struct _pset pset_t
;
49 typedef cap_t pstorage_t
;
51 #elif defined (HAVE_SOLARIS_CAPABILITIES)
52 typedef priv_t pvalue_t
;
53 typedef priv_set_t pset_t
;
54 typedef priv_set_t
*pstorage_t
;
55 #else /* neither LCAPS nor SOLARIS_CAPABILITIES */
56 #error "HAVE_CAPABILITIES defined, but neither LCAPS nor Solaris Capabilties!"
57 #endif /* HAVE_LCAPS */
58 #endif /* HAVE_CAPABILITIES */
60 /* the default NULL state we report is RAISED, but could be LOWERED if
61 * zprivs_terminate is called and the NULL handler is installed.
63 static zebra_privs_current_t zprivs_null_state
= ZPRIVS_RAISED
;
65 /* internal privileges state */
66 static struct _zprivs_t
68 #ifdef HAVE_CAPABILITIES
69 pstorage_t caps
; /* working storage */
70 pset_t
*syscaps_p
; /* system-type requested permitted caps */
71 pset_t
*syscaps_i
; /* system-type requested inheritable caps */
72 #endif /* HAVE_CAPABILITIES */
73 uid_t zuid
, /* uid to run as */
74 zsuid
; /* saved uid */
75 gid_t zgid
; /* gid to run as */
76 gid_t vtygrp
; /* gid for vty sockets */
79 /* externally exported but not directly accessed functions */
80 #ifdef HAVE_CAPABILITIES
81 int zprivs_change_caps (zebra_privs_ops_t
);
82 zebra_privs_current_t
zprivs_state_caps (void);
83 #endif /* HAVE_CAPABILITIES */
84 int zprivs_change_uid (zebra_privs_ops_t
);
85 zebra_privs_current_t
zprivs_state_uid (void);
86 int zprivs_change_null (zebra_privs_ops_t
);
87 zebra_privs_current_t
zprivs_state_null (void);
89 #ifdef HAVE_CAPABILITIES
90 /* internal capability API */
91 static pset_t
*zcaps2sys (zebra_capabilities_t
*, int);
92 static void zprivs_caps_init (struct zebra_privs_t
*);
93 static void zprivs_caps_terminate (void);
95 /* Map of Quagga abstract capabilities to system capabilities */
99 pvalue_t
*system_caps
;
100 } cap_map
[ZCAP_MAX
] =
102 #ifdef HAVE_LCAPS /* Quagga -> Linux capabilities mappings */
103 [ZCAP_SETID
] = { 2, (pvalue_t
[]) { CAP_SETGID
,
105 [ZCAP_BIND
] = { 2, (pvalue_t
[]) { CAP_NET_BIND_SERVICE
,
106 CAP_NET_BROADCAST
}, },
107 [ZCAP_NET_ADMIN
] = { 1, (pvalue_t
[]) { CAP_NET_ADMIN
}, },
108 [ZCAP_NET_RAW
] = { 1, (pvalue_t
[]) { CAP_NET_RAW
}, },
109 [ZCAP_CHROOT
] = { 1, (pvalue_t
[]) { CAP_SYS_CHROOT
, }, },
110 [ZCAP_NICE
] = { 1, (pvalue_t
[]) { CAP_SYS_NICE
}, },
111 [ZCAP_PTRACE
] = { 1, (pvalue_t
[]) { CAP_SYS_PTRACE
}, },
112 [ZCAP_DAC_OVERRIDE
] = { 1, (pvalue_t
[]) { CAP_DAC_OVERRIDE
}, },
113 [ZCAP_READ_SEARCH
] = { 1, (pvalue_t
[]) { CAP_DAC_READ_SEARCH
}, },
114 [ZCAP_SYS_ADMIN
] = { 1, (pvalue_t
[]) { CAP_SYS_ADMIN
}, },
115 [ZCAP_FOWNER
] = { 1, (pvalue_t
[]) { CAP_FOWNER
}, },
116 #elif defined(HAVE_SOLARIS_CAPABILITIES) /* HAVE_LCAPS */
117 /* Quagga -> Solaris privilege mappings */
118 [ZCAP_SETID
] = { 1, (pvalue_t
[]) { PRIV_PROC_SETID
}, },
119 [ZCAP_BIND
] = { 1, (pvalue_t
[]) { PRIV_NET_PRIVADDR
}, },
120 [ZCAP_NET_ADMIN
] = { 1, (pvalue_t
[]) { PRIV_SYS_NET_CONFIG
}, },
121 [ZCAP_NET_RAW
] = { 2, (pvalue_t
[]) { PRIV_NET_RAWACCESS
,
122 PRIV_NET_ICMPACCESS
}, },
123 [ZCAP_CHROOT
] = { 1, (pvalue_t
[]) { PRIV_PROC_CHROOT
}, },
124 [ZCAP_NICE
] = { 1, (pvalue_t
[]) { PRIV_PROC_PRIOCNTL
}, },
125 [ZCAP_PTRACE
] = { 1, (pvalue_t
[]) { PRIV_PROC_SESSION
}, },
126 [ZCAP_DAC_OVERRIDE
] = { 2, (pvalue_t
[]) { PRIV_FILE_DAC_EXECUTE
,
128 PRIV_FILE_DAC_SEARCH
,
130 PRIV_FILE_DAC_SEARCH
}, },
131 [ZCAP_READ_SEARCH
] = { 2, (pvalue_t
[]) { PRIV_FILE_DAC_SEARCH
,
132 PRIV_FILE_DAC_READ
}, },
133 [ZCAP_SYS_ADMIN
] = { 1, (pvalue_t
[]) { PRIV_SYS_ADMIN
}, },
134 [ZCAP_FOWNER
] = { 1, (pvalue_t
[]) { PRIV_FILE_OWNER
}, },
135 #endif /* HAVE_SOLARIS_CAPABILITIES */
139 /* Linux forms of capabilities methods */
140 /* convert zebras privileges to system capabilities */
142 zcaps2sys (zebra_capabilities_t
*zcaps
, int num
)
145 int i
, j
= 0, count
= 0;
150 /* first count up how many system caps we have */
151 for (i
= 0; i
< num
; i
++)
152 count
+= cap_map
[zcaps
[i
]].num
;
154 if ( (syscaps
= XCALLOC (MTYPE_PRIVS
, (sizeof(pset_t
) * num
))) == NULL
)
156 fprintf (stderr
, "%s: could not allocate syscaps!", __func__
);
160 syscaps
->caps
= XCALLOC (MTYPE_PRIVS
, (sizeof (pvalue_t
) * count
));
164 fprintf (stderr
, "%s: could not XCALLOC caps!", __func__
);
168 /* copy the capabilities over */
170 for (i
=0; i
< num
; i
++)
171 for (j
= 0; j
< cap_map
[zcaps
[i
]].num
; j
++)
172 syscaps
->caps
[count
++] = cap_map
[zcaps
[i
]].system_caps
[j
];
174 /* iterations above should be exact same as previous count, obviously.. */
175 syscaps
->num
= count
;
180 /* set or clear the effective capabilities to/from permitted */
182 zprivs_change_caps (zebra_privs_ops_t op
)
184 cap_flag_value_t cflag
;
186 /* should be no possibility of being called without valid caps */
187 assert (zprivs_state
.syscaps_p
&& zprivs_state
.caps
);
188 if (! (zprivs_state
.syscaps_p
&& zprivs_state
.caps
))
191 if (op
== ZPRIVS_RAISE
)
193 else if (op
== ZPRIVS_LOWER
)
198 if ( !cap_set_flag (zprivs_state
.caps
, CAP_EFFECTIVE
,
199 zprivs_state
.syscaps_p
->num
,
200 zprivs_state
.syscaps_p
->caps
,
202 return cap_set_proc (zprivs_state
.caps
);
206 zebra_privs_current_t
207 zprivs_state_caps (void)
210 cap_flag_value_t val
;
212 /* should be no possibility of being called without valid caps */
213 assert (zprivs_state
.syscaps_p
&& zprivs_state
.caps
);
214 if (! (zprivs_state
.syscaps_p
&& zprivs_state
.caps
))
217 for (i
=0; i
< zprivs_state
.syscaps_p
->num
; i
++)
219 if ( cap_get_flag (zprivs_state
.caps
, zprivs_state
.syscaps_p
->caps
[i
],
220 CAP_EFFECTIVE
, &val
) )
222 zlog_warn ("zprivs_state_caps: could not cap_get_flag, %s",
223 safe_strerror (errno
) );
224 return ZPRIVS_UNKNOWN
;
227 return ZPRIVS_RAISED
;
229 return ZPRIVS_LOWERED
;
233 zprivs_caps_init (struct zebra_privs_t
*zprivs
)
235 zprivs_state
.syscaps_p
= zcaps2sys (zprivs
->caps_p
, zprivs
->cap_num_p
);
236 zprivs_state
.syscaps_i
= zcaps2sys (zprivs
->caps_i
, zprivs
->cap_num_i
);
238 /* Tell kernel we want caps maintained across uid changes */
239 if ( prctl(PR_SET_KEEPCAPS
, 1, 0, 0, 0) == -1 )
241 fprintf (stderr
, "privs_init: could not set PR_SET_KEEPCAPS, %s\n",
242 safe_strerror (errno
) );
246 if ( !zprivs_state
.syscaps_p
)
248 fprintf (stderr
, "privs_init: capabilities enabled, "
249 "but no capabilities supplied\n");
252 /* we have caps, we have no need to ever change back the original user */
253 if (zprivs_state
.zuid
)
255 if ( setreuid (zprivs_state
.zuid
, zprivs_state
.zuid
) )
257 fprintf (stderr
, "zprivs_init (cap): could not setreuid, %s\n",
258 safe_strerror (errno
));
263 if ( !(zprivs_state
.caps
= cap_init()) )
265 fprintf (stderr
, "privs_init: failed to cap_init, %s\n",
266 safe_strerror (errno
));
270 if ( cap_clear (zprivs_state
.caps
) )
272 fprintf (stderr
, "privs_init: failed to cap_clear, %s\n",
273 safe_strerror (errno
));
277 /* set permitted caps */
278 cap_set_flag(zprivs_state
.caps
, CAP_PERMITTED
,
279 zprivs_state
.syscaps_p
->num
,
280 zprivs_state
.syscaps_p
->caps
,
283 /* set inheritable caps, if any */
284 if (zprivs_state
.syscaps_i
&& zprivs_state
.syscaps_i
->num
)
286 cap_set_flag(zprivs_state
.caps
, CAP_INHERITABLE
,
287 zprivs_state
.syscaps_i
->num
,
288 zprivs_state
.syscaps_i
->caps
,
292 /* apply caps. CAP_EFFECTIVE is cleared. we'll raise the caps as
293 * and when, and only when, they are needed.
295 if ( cap_set_proc (zprivs_state
.caps
) )
297 fprintf (stderr
, "privs_init: initial cap_set_proc failed\n");
301 /* set methods for the caller to use */
302 zprivs
->change
= zprivs_change_caps
;
303 zprivs
->current_state
= zprivs_state_caps
;
307 zprivs_caps_terminate (void)
309 /* clear all capabilities */
310 if (zprivs_state
.caps
)
311 cap_clear (zprivs_state
.caps
);
313 /* and boom, capabilities are gone forever */
314 if ( cap_set_proc (zprivs_state
.caps
) )
316 fprintf (stderr
, "privs_terminate: cap_set_proc failed, %s",
317 safe_strerror (errno
) );
321 /* free up private state */
322 if (zprivs_state
.syscaps_p
->num
)
324 XFREE (MTYPE_PRIVS
, zprivs_state
.syscaps_p
->caps
);
325 XFREE (MTYPE_PRIVS
, zprivs_state
.syscaps_p
);
328 if (zprivs_state
.syscaps_i
&& zprivs_state
.syscaps_i
->num
)
330 XFREE (MTYPE_PRIVS
, zprivs_state
.syscaps_i
->caps
);
331 XFREE (MTYPE_PRIVS
, zprivs_state
.syscaps_i
);
334 cap_free (zprivs_state
.caps
);
336 #elif defined (HAVE_SOLARIS_CAPABILITIES) /* !HAVE_LCAPS */
338 /* Solaris specific capability/privilege methods
341 * - the 'privileges' man page
342 * - http://cvs.opensolaris.org
343 * - http://blogs.sun.com/roller/page/gbrunett?entry=privilege_enabling_set_id_programs1
346 /* convert zebras privileges to system capabilities */
348 zcaps2sys (zebra_capabilities_t
*zcaps
, int num
)
353 if ((syscaps
= priv_allocset()) == NULL
)
355 fprintf (stderr
, "%s: could not allocate syscaps!\n", __func__
);
359 priv_emptyset (syscaps
);
361 for (i
=0; i
< num
; i
++)
362 for (j
= 0; j
< cap_map
[zcaps
[i
]].num
; j
++)
363 priv_addset (syscaps
, cap_map
[zcaps
[i
]].system_caps
[j
]);
368 /* callback exported to users to RAISE and LOWER effective privileges
369 * from nothing to the given permitted set and back down
372 zprivs_change_caps (zebra_privs_ops_t op
)
375 /* should be no possibility of being called without valid caps */
376 assert (zprivs_state
.syscaps_p
);
377 if (!zprivs_state
.syscaps_p
)
379 fprintf (stderr
, "%s: Eek, missing caps!", __func__
);
383 /* to raise: copy original permitted into our working effective set
384 * to lower: just clear the working effective set
386 if (op
== ZPRIVS_RAISE
)
387 priv_copyset (zprivs_state
.syscaps_p
, zprivs_state
.caps
);
388 else if (op
== ZPRIVS_LOWER
)
389 priv_emptyset (zprivs_state
.caps
);
393 if (setppriv (PRIV_SET
, PRIV_EFFECTIVE
, zprivs_state
.caps
) != 0)
399 /* Retrieve current privilege state, is it RAISED or LOWERED? */
400 zebra_privs_current_t
401 zprivs_state_caps (void)
403 zebra_privs_current_t result
;
406 if ( (effective
= priv_allocset()) == NULL
)
408 fprintf (stderr
, "%s: failed to get priv_allocset! %s\n", __func__
,
409 safe_strerror (errno
));
410 return ZPRIVS_UNKNOWN
;
413 if (getppriv (PRIV_EFFECTIVE
, effective
))
415 fprintf (stderr
, "%s: failed to get state! %s\n", __func__
,
416 safe_strerror (errno
));
417 result
= ZPRIVS_UNKNOWN
;
421 if (priv_isemptyset (effective
) == B_TRUE
)
422 result
= ZPRIVS_LOWERED
;
424 result
= ZPRIVS_RAISED
;
428 priv_freeset (effective
);
434 zprivs_caps_init (struct zebra_privs_t
*zprivs
)
439 /* the specified sets */
440 zprivs_state
.syscaps_p
= zcaps2sys (zprivs
->caps_p
, zprivs
->cap_num_p
);
441 zprivs_state
.syscaps_i
= zcaps2sys (zprivs
->caps_i
, zprivs
->cap_num_i
);
443 /* nonsensical to have gotten here but not have capabilities */
444 if (!zprivs_state
.syscaps_p
)
446 fprintf (stderr
, "%s: capabilities enabled, "
447 "but no valid capabilities supplied\n",
451 /* We retain the basic set in our permitted set, as Linux has no
452 * equivalent. The basic set on Linux hence is implicit, always
455 if ((basic
= priv_str_to_set("basic", ",", NULL
)) == NULL
)
457 fprintf (stderr
, "%s: couldn't get basic set!\n", __func__
);
461 /* Add the basic set to the permitted set */
462 priv_union (basic
, zprivs_state
.syscaps_p
);
463 priv_freeset (basic
);
465 /* we need an empty set for 'effective', potentially for inheritable too */
466 if ( (empty
= priv_allocset()) == NULL
)
468 fprintf (stderr
, "%s: couldn't get empty set!\n", __func__
);
471 priv_emptyset (empty
);
473 /* Hey kernel, we know about privileges!
474 * this isn't strictly required, use of setppriv should have same effect
476 if (setpflags (PRIV_AWARE
, 1))
478 fprintf (stderr
, "%s: error setting PRIV_AWARE!, %s\n", __func__
,
479 safe_strerror (errno
) );
483 /* need either valid or empty sets for both p and i.. */
484 assert (zprivs_state
.syscaps_i
&& zprivs_state
.syscaps_p
);
486 /* we have caps, we have no need to ever change back the original user
487 * change real, effective and saved to the specified user.
489 if (zprivs_state
.zuid
)
491 if ( setreuid (zprivs_state
.zuid
, zprivs_state
.zuid
) )
493 fprintf (stderr
, "%s: could not setreuid, %s\n",
494 __func__
, safe_strerror (errno
));
499 /* set the permitted set */
500 if (setppriv (PRIV_SET
, PRIV_PERMITTED
, zprivs_state
.syscaps_p
))
502 fprintf (stderr
, "%s: error setting permitted set!, %s\n", __func__
,
503 safe_strerror (errno
) );
507 /* set the inheritable set */
508 if (setppriv (PRIV_SET
, PRIV_INHERITABLE
, zprivs_state
.syscaps_i
))
510 fprintf (stderr
, "%s: error setting inheritable set!, %s\n", __func__
,
511 safe_strerror (errno
) );
515 /* now clear the effective set and we're ready to go */
516 if (setppriv (PRIV_SET
, PRIV_EFFECTIVE
, empty
))
518 fprintf (stderr
, "%s: error setting effective set!, %s\n", __func__
,
519 safe_strerror (errno
) );
523 /* we'll use this as our working-storage privset */
524 zprivs_state
.caps
= empty
;
526 /* set methods for the caller to use */
527 zprivs
->change
= zprivs_change_caps
;
528 zprivs
->current_state
= zprivs_state_caps
;
532 zprivs_caps_terminate (void)
534 assert (zprivs_state
.caps
);
536 /* clear all capabilities */
537 priv_emptyset (zprivs_state
.caps
);
538 setppriv (PRIV_SET
, PRIV_EFFECTIVE
, zprivs_state
.caps
);
539 setppriv (PRIV_SET
, PRIV_PERMITTED
, zprivs_state
.caps
);
540 setppriv (PRIV_SET
, PRIV_INHERITABLE
, zprivs_state
.caps
);
542 /* free up private state */
543 if (zprivs_state
.syscaps_p
)
544 priv_freeset (zprivs_state
.syscaps_p
);
545 if (zprivs_state
.syscaps_i
)
546 priv_freeset (zprivs_state
.syscaps_i
);
548 priv_freeset (zprivs_state
.caps
);
550 #else /* !HAVE_LCAPS && ! HAVE_SOLARIS_CAPABILITIES */
551 #error "Neither Solaris nor Linux capabilities, dazed and confused..."
552 #endif /* HAVE_LCAPS */
553 #endif /* HAVE_CAPABILITIES */
556 zprivs_change_uid (zebra_privs_ops_t op
)
559 if (op
== ZPRIVS_RAISE
)
560 return seteuid (zprivs_state
.zsuid
);
561 else if (op
== ZPRIVS_LOWER
)
562 return seteuid (zprivs_state
.zuid
);
567 zebra_privs_current_t
568 zprivs_state_uid (void)
570 return ( (zprivs_state
.zuid
== geteuid()) ? ZPRIVS_LOWERED
: ZPRIVS_RAISED
);
574 zprivs_change_null (zebra_privs_ops_t op
)
579 zebra_privs_current_t
580 zprivs_state_null (void)
582 return zprivs_null_state
;
586 zprivs_init(struct zebra_privs_t
*zprivs
)
588 struct passwd
*pwentry
= NULL
;
589 struct group
*grentry
= NULL
;
593 fprintf (stderr
, "zprivs_init: called with NULL arg!\n");
598 if (! (zprivs
->user
|| zprivs
->group
599 || zprivs
->cap_num_p
|| zprivs
->cap_num_i
) )
601 zprivs
->change
= zprivs_change_null
;
602 zprivs
->current_state
= zprivs_state_null
;
608 if ( (pwentry
= getpwnam (zprivs
->user
)) )
610 zprivs_state
.zuid
= pwentry
->pw_uid
;
614 /* cant use log.h here as it depends on vty */
615 fprintf (stderr
, "privs_init: could not lookup user %s\n",
623 if (zprivs
->vty_group
)
624 /* Add the vty_group to the supplementary groups so it can be chowned to */
626 if ( (grentry
= getgrnam (zprivs
->vty_group
)) )
628 zprivs_state
.vtygrp
= grentry
->gr_gid
;
629 if ( setgroups (1, &zprivs_state
.vtygrp
) )
631 fprintf (stderr
, "privs_init: could not setgroups, %s\n",
632 safe_strerror (errno
) );
638 fprintf (stderr
, "privs_init: could not lookup vty group %s\n",
646 if ( (grentry
= getgrnam (zprivs
->group
)) )
648 zprivs_state
.zgid
= grentry
->gr_gid
;
652 fprintf (stderr
, "privs_init: could not lookup group %s\n",
656 /* change group now, forever. uid we do later */
657 if ( setregid (zprivs_state
.zgid
, zprivs_state
.zgid
) )
659 fprintf (stderr
, "zprivs_init: could not setregid, %s\n",
660 safe_strerror (errno
) );
665 #ifdef HAVE_CAPABILITIES
666 zprivs_caps_init (zprivs
);
667 #else /* !HAVE_CAPABILITIES */
668 /* we dont have caps. we'll need to maintain rid and saved uid
669 * and change euid back to saved uid (who we presume has all neccessary
670 * privileges) whenever we are asked to raise our privileges.
672 * This is not worth that much security wise, but all we can do.
674 zprivs_state
.zsuid
= geteuid();
675 if ( zprivs_state
.zuid
)
677 if ( setreuid (-1, zprivs_state
.zuid
) )
679 fprintf (stderr
, "privs_init (uid): could not setreuid, %s\n",
680 safe_strerror (errno
));
685 zprivs
->change
= zprivs_change_uid
;
686 zprivs
->current_state
= zprivs_state_uid
;
687 #endif /* HAVE_CAPABILITIES */
691 zprivs_terminate (struct zebra_privs_t
*zprivs
)
695 fprintf (stderr
, "%s: no privs struct given, terminating", __func__
);
699 #ifdef HAVE_CAPABILITIES
700 zprivs_caps_terminate();
701 #else /* !HAVE_CAPABILITIES */
702 if (zprivs_state
.zuid
)
704 if ( setreuid (zprivs_state
.zuid
, zprivs_state
.zuid
) )
706 fprintf (stderr
, "privs_terminate: could not setreuid, %s",
707 safe_strerror (errno
) );
711 #endif /* HAVE_LCAPS */
713 zprivs
->change
= zprivs_change_null
;
714 zprivs
->current_state
= zprivs_state_null
;
715 zprivs_null_state
= ZPRIVS_LOWERED
;
720 zprivs_get_ids(struct zprivs_ids_t
*ids
)
723 ids
->uid_priv
= getuid();
724 (zprivs_state
.zuid
) ? (ids
->uid_normal
= zprivs_state
.zuid
)
725 : (ids
->uid_normal
= -1);
726 (zprivs_state
.zgid
) ? (ids
->gid_normal
= zprivs_state
.zgid
)
727 : (ids
->gid_normal
= -1);
728 (zprivs_state
.vtygrp
) ? (ids
->gid_vty
= zprivs_state
.vtygrp
)
729 : (ids
->gid_vty
= -1);