freebsd-dev/sys/security/mac/mac_internal.h
Mateusz Guzik 6dcf45feda mac: reduce pessimization of sdt probe handling
Prior to the change the code would branch on return value and then check
if probes are enabled. Since vast majority of the time they are not, this
is clearly wasteful. Check probes first.

Sponsored by:	The FreeBSD Foundation
2018-12-19 22:30:26 +00:00

521 lines
18 KiB
C

/*-
* Copyright (c) 1999-2002, 2006, 2009 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.
* Copyright (c) 2009 Apple, 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").
*
* This software was developed at the University of Cambridge Computer
* Laboratory with support from a grant from Google, Inc.
*
* 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
#include <sys/lock.h>
#include <sys/rmlock.h>
/*
* MAC Framework sysctl namespace.
*/
#ifdef SYSCTL_DECL
SYSCTL_DECL(_security_mac);
#endif /* SYSCTL_DECL */
/*
* MAC Framework SDT DTrace probe namespace, macros for declaring entry
* point probes, macros for invoking them.
*/
#ifdef SDT_PROVIDER_DECLARE
SDT_PROVIDER_DECLARE(mac); /* MAC Framework-level events. */
SDT_PROVIDER_DECLARE(mac_framework); /* Entry points to MAC. */
#define MAC_CHECK_PROBE_DEFINE4(name, arg0, arg1, arg2, arg3) \
SDT_PROBE_DEFINE5(mac_framework, , name, mac__check__err, \
"int", arg0, arg1, arg2, arg3); \
SDT_PROBE_DEFINE5(mac_framework, , name, mac__check__ok, \
"int", arg0, arg1, arg2, arg3);
#define MAC_CHECK_PROBE_DEFINE3(name, arg0, arg1, arg2) \
SDT_PROBE_DEFINE4(mac_framework, , name, mac__check__err, \
"int", arg0, arg1, arg2); \
SDT_PROBE_DEFINE4(mac_framework, , name, mac__check__ok, \
"int", arg0, arg1, arg2);
#define MAC_CHECK_PROBE_DEFINE2(name, arg0, arg1) \
SDT_PROBE_DEFINE3(mac_framework, , name, mac__check__err, \
"int", arg0, arg1); \
SDT_PROBE_DEFINE3(mac_framework, , name, mac__check__ok, \
"int", arg0, arg1);
#define MAC_CHECK_PROBE_DEFINE1(name, arg0) \
SDT_PROBE_DEFINE2(mac_framework, , name, mac__check__err, \
"int", arg0); \
SDT_PROBE_DEFINE2(mac_framework, , name, mac__check__ok, \
"int", arg0);
#define MAC_CHECK_PROBE4(name, error, arg0, arg1, arg2, arg3) do { \
if (SDT_PROBES_ENABLED()) { \
if (error) { \
SDT_PROBE5(mac_framework, , name, mac__check__err,\
error, arg0, arg1, arg2, arg3); \
} else { \
SDT_PROBE5(mac_framework, , name, mac__check__ok,\
0, arg0, arg1, arg2, arg3); \
} \
} \
} while (0)
#define MAC_CHECK_PROBE3(name, error, arg0, arg1, arg2) \
MAC_CHECK_PROBE4(name, error, arg0, arg1, arg2, 0)
#define MAC_CHECK_PROBE2(name, error, arg0, arg1) \
MAC_CHECK_PROBE3(name, error, arg0, arg1, 0)
#define MAC_CHECK_PROBE1(name, error, arg0) \
MAC_CHECK_PROBE2(name, error, arg0, 0)
#endif
#define MAC_GRANT_PROBE_DEFINE2(name, arg0, arg1) \
SDT_PROBE_DEFINE3(mac_framework, , name, mac__grant__err, \
"int", arg0, arg1); \
SDT_PROBE_DEFINE3(mac_framework, , name, mac__grant__ok, \
"int", arg0, arg1);
#define MAC_GRANT_PROBE2(name, error, arg0, arg1) do { \
if (SDT_PROBES_ENABLED()) { \
if (error) { \
SDT_PROBE3(mac_framework, , name, mac__grant__err,\
error, arg0, arg1); \
} else { \
SDT_PROBE3(mac_framework, , name, mac__grant__ok,\
error, arg0, arg1); \
} \
} \
} while (0)
/*
* 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];
};
/*
* Flags for mac_labeled, a bitmask of object types need across the union of
* all policies currently registered with the MAC Framework, used to key
* whether or not labels are allocated and constructors for the type are
* invoked.
*/
#define MPC_OBJECT_CRED 0x0000000000000001
#define MPC_OBJECT_PROC 0x0000000000000002
#define MPC_OBJECT_VNODE 0x0000000000000004
#define MPC_OBJECT_INPCB 0x0000000000000008
#define MPC_OBJECT_SOCKET 0x0000000000000010
#define MPC_OBJECT_DEVFS 0x0000000000000020
#define MPC_OBJECT_MBUF 0x0000000000000040
#define MPC_OBJECT_IPQ 0x0000000000000080
#define MPC_OBJECT_IFNET 0x0000000000000100
#define MPC_OBJECT_BPFDESC 0x0000000000000200
#define MPC_OBJECT_PIPE 0x0000000000000400
#define MPC_OBJECT_MOUNT 0x0000000000000800
#define MPC_OBJECT_POSIXSEM 0x0000000000001000
#define MPC_OBJECT_POSIXSHM 0x0000000000002000
#define MPC_OBJECT_SYSVMSG 0x0000000000004000
#define MPC_OBJECT_SYSVMSQ 0x0000000000008000
#define MPC_OBJECT_SYSVSEM 0x0000000000010000
#define MPC_OBJECT_SYSVSHM 0x0000000000020000
#define MPC_OBJECT_SYNCACHE 0x0000000000040000
#define MPC_OBJECT_IP6Q 0x0000000000080000
/*
* MAC Framework global variables.
*/
extern struct mac_policy_list_head mac_policy_list;
extern struct mac_policy_list_head mac_static_policy_list;
extern u_int mac_policy_count;
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_slock_nosleep(struct rm_priotracker *tracker);
void mac_policy_slock_sleep(void);
void mac_policy_sunlock_nosleep(struct rm_priotracker *tracker);
void mac_policy_sunlock_sleep(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 Framework composition macros invoke all registered MAC policies for a
* specific entry point. They come in two forms: one which permits policies
* to sleep/block, and another that does not.
*
* MAC_POLICY_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_POLICY_CHECK(check, args...) do { \
struct mac_policy_conf *mpc; \
\
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 (!LIST_EMPTY(&mac_policy_list)) { \
mac_policy_slock_sleep(); \
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_sunlock_sleep(); \
} \
} while (0)
#define MAC_POLICY_CHECK_NOSLEEP(check, args...) do { \
struct mac_policy_conf *mpc; \
\
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 (!LIST_EMPTY(&mac_policy_list)) { \
struct rm_priotracker tracker; \
\
mac_policy_slock_nosleep(&tracker); \
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_sunlock_nosleep(&tracker); \
} \
} while (0)
/*
* MAC_POLICY_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_POLICY_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_POLICY_GRANT_NOSLEEP(check, args...) do { \
struct mac_policy_conf *mpc; \
\
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 (!LIST_EMPTY(&mac_policy_list)) { \
struct rm_priotracker tracker; \
\
mac_policy_slock_nosleep(&tracker); \
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_sunlock_nosleep(&tracker); \
} \
} while (0)
/*
* MAC_POLICY_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_POLICY_BOOLEAN(operation, composition, args...) do { \
struct mac_policy_conf *mpc; \
\
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 (!LIST_EMPTY(&mac_policy_list)) { \
mac_policy_slock_sleep(); \
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_sunlock_sleep(); \
} \
} while (0)
#define MAC_POLICY_BOOLEAN_NOSLEEP(operation, composition, args...) do {\
struct mac_policy_conf *mpc; \
\
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 (!LIST_EMPTY(&mac_policy_list)) { \
struct rm_priotracker tracker; \
\
mac_policy_slock_nosleep(&tracker); \
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_sunlock_nosleep(&tracker); \
} \
} while (0)
/*
* MAC_POLICY_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_POLICY_EXTERNALIZE, and an error is returned if any element is matched
* by no policy.
*/
#define MAC_POLICY_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_POLICY_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_POLICY_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_POLICY_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_POLICY_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_POLICY_PERFORM performs the designated operation by walking the policy
* module list and invoking that operation for each policy.
*/
#define MAC_POLICY_PERFORM(operation, args...) do { \
struct mac_policy_conf *mpc; \
\
LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
mpc->mpc_ops->mpo_ ## operation (args); \
} \
if (!LIST_EMPTY(&mac_policy_list)) { \
mac_policy_slock_sleep(); \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
mpc->mpc_ops->mpo_ ## operation (args); \
} \
mac_policy_sunlock_sleep(); \
} \
} while (0)
#define MAC_POLICY_PERFORM_NOSLEEP(operation, args...) do { \
struct mac_policy_conf *mpc; \
\
LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
mpc->mpc_ops->mpo_ ## operation (args); \
} \
if (!LIST_EMPTY(&mac_policy_list)) { \
struct rm_priotracker tracker; \
\
mac_policy_slock_nosleep(&tracker); \
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { \
if (mpc->mpc_ops->mpo_ ## operation != NULL) \
mpc->mpc_ops->mpo_ ## operation (args); \
} \
mac_policy_sunlock_nosleep(&tracker); \
} \
} while (0)
#endif /* !_SECURITY_MAC_MAC_INTERNAL_H_ */