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freebsd-nq/sys/security/mac/mac_internal.h
Robert Watson 6356dba0b4 Introduce two related changes to the TrustedBSD MAC Framework: 
(1) Abstract interpreter vnode labeling in execve(2) and mac_execve(2)
    so that the general exec code isn't aware of the details of
    allocating, copying, and freeing labels, rather, simply passes in
    a void pointer to start and stop functions that will be used by
    the framework.  This change will be MFC'd.

(2) Introduce a new flags field to the MAC_POLICY_SET(9) interface
    allowing policies to declare which types of objects require label
    allocation, initialization, and destruction, and define a set of
    flags covering various supported object types (MPC_OBJECT_PROC,
    MPC_OBJECT_VNODE, MPC_OBJECT_INPCB, ...).  This change reduces the
    overhead of compiling the MAC Framework into the kernel if policies
    aren't loaded, or if policies require labels on only a small number
    or even no object types.  Each time a policy is loaded or unloaded,
    we recalculate a mask of labeled object types across all policies
    present in the system.  Eliminate MAC_ALWAYS_LABEL_MBUF option as it
    is no longer required.

MFC after:	1 week ((1) only)
Reviewed by:	csjp
Obtained from:	TrustedBSD Project
Sponsored by:	Apple, Inc.
2008-08-23 15:26:36 +00:00

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/*-
* Copyright (c) 1999-2002, 2006 Robert N. M. Watson
* Copyright (c) 2001 Ilmar S. Habibulin
* Copyright (c) 2001-2004 Networks Associates Technology, Inc.
* Copyright (c) 2006 nCircle Network Security, Inc.
* Copyright (c) 2006 SPARTA, Inc.
* All rights reserved.
*
* This software was developed by Robert Watson and Ilmar Habibulin for the
* TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research program.
*
* This software was developed by Robert N. M. Watson for the TrustedBSD
* Project under contract to nCircle Network Security, Inc.
*
* This software was enhanced by SPARTA ISSO under SPAWAR contract
* N66001-04-C-6019 ("SEFOS").
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _SECURITY_MAC_MAC_INTERNAL_H_
#define _SECURITY_MAC_MAC_INTERNAL_H_
#ifndef _KERNEL
#error "no user-serviceable parts inside"
#endif
/*
* MAC Framework sysctl namespace.
*/
#ifdef SYSCTL_DECL
SYSCTL_DECL(_security_mac);
#endif /* SYSCTL_DECL */
/*
* MAC Framework global types and typedefs.
*/
LIST_HEAD(mac_policy_list_head, mac_policy_conf);
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_MACTEMP);
#endif
/*
* MAC labels -- in-kernel storage format.
*
* In general, struct label pointers are embedded in kernel data structures
* representing objects that may be labeled (and protected). Struct label is
* opaque to both kernel services that invoke the MAC Framework and MAC
* policy modules. In particular, we do not wish to encode the layout of the
* label structure into any ABIs. Historically, the slot array contained
* unions of {long, void} but now contains uintptr_t.
*/
#define MAC_MAX_SLOTS 4
#define MAC_FLAG_INITIALIZED 0x0000001 /* Is initialized for use. */
struct label {
int l_flags;
intptr_t l_perpolicy[MAC_MAX_SLOTS];
};
/*
* MAC Framework global variables.
*/
extern struct mac_policy_list_head mac_policy_list;
extern struct mac_policy_list_head mac_static_policy_list;
extern uint64_t mac_labeled;
extern struct mtx mac_ifnet_mtx;
/*
* MAC Framework infrastructure functions.
*/
int mac_error_select(int error1, int error2);
void mac_policy_grab_exclusive(void);
void mac_policy_assert_exclusive(void);
void mac_policy_release_exclusive(void);
void mac_policy_list_busy(void);
int mac_policy_list_conditional_busy(void);
void mac_policy_list_unbusy(void);
struct label *mac_labelzone_alloc(int flags);
void mac_labelzone_free(struct label *label);
void mac_labelzone_init(void);
void mac_init_label(struct label *label);
void mac_destroy_label(struct label *label);
int mac_check_structmac_consistent(struct mac *mac);
int mac_allocate_slot(void);
#define MAC_IFNET_LOCK(ifp) mtx_lock(&mac_ifnet_mtx)
#define MAC_IFNET_UNLOCK(ifp) mtx_unlock(&mac_ifnet_mtx)
/*
* MAC Framework per-object type functions. It's not yet clear how the
* namespaces, etc, should work for these, so for now, sort by object type.
*/
struct label *mac_cred_label_alloc(void);
void mac_cred_label_free(struct label *label);
struct label *mac_pipe_label_alloc(void);
void mac_pipe_label_free(struct label *label);
struct label *mac_socket_label_alloc(int flag);
void mac_socket_label_free(struct label *label);
struct label *mac_vnode_label_alloc(void);
void mac_vnode_label_free(struct label *label);
int mac_cred_check_relabel(struct ucred *cred, struct label *newlabel);
int mac_cred_externalize_label(struct label *label, char *elements,
char *outbuf, size_t outbuflen);
int mac_cred_internalize_label(struct label *label, char *string);
void mac_cred_relabel(struct ucred *cred, struct label *newlabel);
struct label *mac_mbuf_to_label(struct mbuf *m);
void mac_pipe_copy_label(struct label *src, struct label *dest);
int mac_pipe_externalize_label(struct label *label, char *elements,
char *outbuf, size_t outbuflen);
int mac_pipe_internalize_label(struct label *label, char *string);
int mac_socket_label_set(struct ucred *cred, struct socket *so,
struct label *label);
void mac_socket_copy_label(struct label *src, struct label *dest);
int mac_socket_externalize_label(struct label *label, char *elements,
char *outbuf, size_t outbuflen);
int mac_socket_internalize_label(struct label *label, char *string);
int mac_vnode_externalize_label(struct label *label, char *elements,
char *outbuf, size_t outbuflen);
int mac_vnode_internalize_label(struct label *label, char *string);
void mac_vnode_check_mmap_downgrade(struct ucred *cred, struct vnode *vp,
int *prot);
int vn_setlabel(struct vnode *vp, struct label *intlabel,
struct ucred *cred);
/*
* MAC_CHECK performs the designated check by walking the policy module list
* and checking with each as to how it feels about the request. Note that it
* returns its value via 'error' in the scope of the caller.
*/
#define MAC_CHECK(check, args...) do { \
struct mac_policy_conf *mpc; \
int entrycount; \
\
error = 0; \
LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## check != NULL) \
error = mac_error_select( \
mpc->mpc_ops->mpo_ ## check (args), \
error); \
} \
if ((entrycount = mac_policy_list_conditional_busy()) != 0) { \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## check != NULL) \
error = mac_error_select( \
mpc->mpc_ops->mpo_ ## check (args), \
error); \
} \
mac_policy_list_unbusy(); \
} \
} while (0)
/*
* MAC_GRANT performs the designated check by walking the policy module list
* and checking with each as to how it feels about the request. Unlike
* MAC_CHECK, it grants if any policies return '0', and otherwise returns
* EPERM. Note that it returns its value via 'error' in the scope of the
* caller.
*/
#define MAC_GRANT(check, args...) do { \
struct mac_policy_conf *mpc; \
int entrycount; \
\
error = EPERM; \
LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## check != NULL) { \
if (mpc->mpc_ops->mpo_ ## check(args) == 0) \
error = 0; \
} \
} \
if ((entrycount = mac_policy_list_conditional_busy()) != 0) { \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## check != NULL) { \
if (mpc->mpc_ops->mpo_ ## check (args) \
== 0) \
error = 0; \
} \
} \
mac_policy_list_unbusy(); \
} \
} while (0)
/*
* MAC_BOOLEAN performs the designated boolean composition by walking the
* module list, invoking each instance of the operation, and combining the
* results using the passed C operator. Note that it returns its value via
* 'result' in the scope of the caller, which should be initialized by the
* caller in a meaningful way to get a meaningful result.
*/
#define MAC_BOOLEAN(operation, composition, args...) do { \
struct mac_policy_conf *mpc; \
int entrycount; \
\
LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
result = result composition \
mpc->mpc_ops->mpo_ ## operation (args); \
} \
if ((entrycount = mac_policy_list_conditional_busy()) != 0) { \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
result = result composition \
mpc->mpc_ops->mpo_ ## operation \
(args); \
} \
mac_policy_list_unbusy(); \
} \
} while (0)
/*
* MAC_EXTERNALIZE queries each policy to see if it can generate an
* externalized version of a label element by name. Policies declare whether
* they have matched a particular element name, parsed from the string by
* MAC_EXTERNALIZE, and an error is returned if any element is matched by no
* policy.
*/
#define MAC_EXTERNALIZE(type, label, elementlist, outbuf, \
outbuflen) do { \
int claimed, first, ignorenotfound, savedlen; \
char *element_name, *element_temp; \
struct sbuf sb; \
\
error = 0; \
first = 1; \
sbuf_new(&sb, outbuf, outbuflen, SBUF_FIXEDLEN); \
element_temp = elementlist; \
while ((element_name = strsep(&element_temp, ",")) != NULL) { \
if (element_name[0] == '?') { \
element_name++; \
ignorenotfound = 1; \
} else \
ignorenotfound = 0; \
savedlen = sbuf_len(&sb); \
if (first) \
error = sbuf_printf(&sb, "%s/", element_name); \
else \
error = sbuf_printf(&sb, ",%s/", element_name); \
if (error == -1) { \
error = EINVAL; /* XXX: E2BIG? */ \
break; \
} \
claimed = 0; \
MAC_CHECK(type ## _externalize_label, label, \
element_name, &sb, &claimed); \
if (error) \
break; \
if (claimed == 0 && ignorenotfound) { \
/* Revert last label name. */ \
sbuf_setpos(&sb, savedlen); \
} else if (claimed != 1) { \
error = EINVAL; /* XXX: ENOLABEL? */ \
break; \
} else { \
first = 0; \
} \
} \
sbuf_finish(&sb); \
} while (0)
/*
* MAC_INTERNALIZE presents parsed element names and data to each policy to
* see if any is willing to claim it and internalize the label data. If no
* policies match, an error is returned.
*/
#define MAC_INTERNALIZE(type, label, instring) do { \
char *element, *element_name, *element_data; \
int claimed; \
\
error = 0; \
element = instring; \
while ((element_name = strsep(&element, ",")) != NULL) { \
element_data = element_name; \
element_name = strsep(&element_data, "/"); \
if (element_data == NULL) { \
error = EINVAL; \
break; \
} \
claimed = 0; \
MAC_CHECK(type ## _internalize_label, label, \
element_name, element_data, &claimed); \
if (error) \
break; \
if (claimed != 1) { \
/* XXXMAC: Another error here? */ \
error = EINVAL; \
break; \
} \
} \
} while (0)
/*
* MAC_PERFORM performs the designated operation by walking the policy module
* list and invoking that operation for each policy.
*/
#define MAC_PERFORM(operation, args...) do { \
struct mac_policy_conf *mpc; \
int entrycount; \
\
LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
mpc->mpc_ops->mpo_ ## operation (args); \
} \
if ((entrycount = mac_policy_list_conditional_busy()) != 0) { \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
mpc->mpc_ops->mpo_ ## operation (args); \
} \
mac_policy_list_unbusy(); \
} \
} while (0)
#endif /* !_SECURITY_MAC_MAC_INTERNAL_H_ */
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