HardenedBSD/sys/security/mac/mac_internal.h
Michael Tuexen 2fb778fab8 MAC: improve handling of listening sockets
so_peerlabel can only be used when the socket is not listening.

Reviewed by:		markj
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D46755
2024-09-26 08:06:24 +02:00

535 lines
18 KiB
C

/*-
* Copyright (c) 1999-2002, 2006, 2009, 2019 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.
*/
#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(const struct mac *mac);
int mac_allocate_slot(void);
/*
* Lock ifnets to protect labels only if ifnet labels are in use.
*/
#define MAC_IFNET_LOCK(ifp, locked) do { \
if (mac_labeled & MPC_OBJECT_IFNET) { \
mtx_lock(&mac_ifnet_mtx); \
locked = 1; \
} else { \
locked = 0; \
} \
} while (0)
#define MAC_IFNET_UNLOCK(ifp, locked) do { \
if (locked) { \
mtx_unlock(&mac_ifnet_mtx); \
locked = 0; \
} \
} while (0)
/*
* 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);
void mac_socketpeer_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_ */