freebsd-skq/sys/security/mac/mac_inet.c
Robert Watson 5c95417dad When MAC is enabled and a policy module is loaded, don't unconditionally
lock mac_ifnet_mtx, which protects labels on struct ifnet, unless at least
one policy is actively using labels on ifnets.  This avoids a global mutex
acquire in certain fast paths -- most noticeably ifnet transmit.  This was
previously invisible by default, as no MAC policies were loaded by default,
but recently became visible due to mac_ntpd being enabled by default.

gallatin@ reports a reduction in PPS overhead from 300% to 2.2% with this
change.  We will want to explore further MAC Framework optimisation to
reduce overhead further, but this brings things more back into the world
of the sane.

MFC after:	3 days
2019-05-03 20:38:43 +00:00

510 lines
11 KiB
C

/*-
* Copyright (c) 1999-2002, 2007, 2009, 2019 Robert N. M. Watson
* Copyright (c) 2001 Ilmar S. Habibulin
* Copyright (c) 2001-2004 Networks Associates Technology, Inc.
* Copyright (c) 2006 SPARTA, Inc.
* Copyright (c) 2008 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 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sbuf.h>
#include <sys/sdt.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
#include <security/mac/mac_policy.h>
static struct label *
mac_inpcb_label_alloc(int flag)
{
struct label *label;
int error;
label = mac_labelzone_alloc(flag);
if (label == NULL)
return (NULL);
if (flag & M_WAITOK)
MAC_POLICY_CHECK(inpcb_init_label, label, flag);
else
MAC_POLICY_CHECK_NOSLEEP(inpcb_init_label, label, flag);
if (error) {
MAC_POLICY_PERFORM_NOSLEEP(inpcb_destroy_label, label);
mac_labelzone_free(label);
return (NULL);
}
return (label);
}
int
mac_inpcb_init(struct inpcb *inp, int flag)
{
if (mac_labeled & MPC_OBJECT_INPCB) {
inp->inp_label = mac_inpcb_label_alloc(flag);
if (inp->inp_label == NULL)
return (ENOMEM);
} else
inp->inp_label = NULL;
return (0);
}
static struct label *
mac_ipq_label_alloc(int flag)
{
struct label *label;
int error;
label = mac_labelzone_alloc(flag);
if (label == NULL)
return (NULL);
if (flag & M_WAITOK)
MAC_POLICY_CHECK(ipq_init_label, label, flag);
else
MAC_POLICY_CHECK_NOSLEEP(ipq_init_label, label, flag);
if (error) {
MAC_POLICY_PERFORM_NOSLEEP(ipq_destroy_label, label);
mac_labelzone_free(label);
return (NULL);
}
return (label);
}
int
mac_ipq_init(struct ipq *q, int flag)
{
if (mac_labeled & MPC_OBJECT_IPQ) {
q->ipq_label = mac_ipq_label_alloc(flag);
if (q->ipq_label == NULL)
return (ENOMEM);
} else
q->ipq_label = NULL;
return (0);
}
static void
mac_inpcb_label_free(struct label *label)
{
MAC_POLICY_PERFORM_NOSLEEP(inpcb_destroy_label, label);
mac_labelzone_free(label);
}
void
mac_inpcb_destroy(struct inpcb *inp)
{
if (inp->inp_label != NULL) {
mac_inpcb_label_free(inp->inp_label);
inp->inp_label = NULL;
}
}
static void
mac_ipq_label_free(struct label *label)
{
MAC_POLICY_PERFORM_NOSLEEP(ipq_destroy_label, label);
mac_labelzone_free(label);
}
void
mac_ipq_destroy(struct ipq *q)
{
if (q->ipq_label != NULL) {
mac_ipq_label_free(q->ipq_label);
q->ipq_label = NULL;
}
}
void
mac_inpcb_create(struct socket *so, struct inpcb *inp)
{
MAC_POLICY_PERFORM_NOSLEEP(inpcb_create, so, so->so_label, inp,
inp->inp_label);
}
void
mac_ipq_reassemble(struct ipq *q, struct mbuf *m)
{
struct label *label;
if (mac_policy_count == 0)
return;
label = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(ipq_reassemble, q, q->ipq_label, m,
label);
}
void
mac_netinet_fragment(struct mbuf *m, struct mbuf *frag)
{
struct label *mlabel, *fraglabel;
if (mac_policy_count == 0)
return;
mlabel = mac_mbuf_to_label(m);
fraglabel = mac_mbuf_to_label(frag);
MAC_POLICY_PERFORM_NOSLEEP(netinet_fragment, m, mlabel, frag,
fraglabel);
}
void
mac_ipq_create(struct mbuf *m, struct ipq *q)
{
struct label *label;
if (mac_policy_count == 0)
return;
label = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(ipq_create, m, label, q, q->ipq_label);
}
void
mac_inpcb_create_mbuf(struct inpcb *inp, struct mbuf *m)
{
struct label *mlabel;
INP_LOCK_ASSERT(inp);
if (mac_policy_count == 0)
return;
mlabel = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(inpcb_create_mbuf, inp, inp->inp_label, m,
mlabel);
}
int
mac_ipq_match(struct mbuf *m, struct ipq *q)
{
struct label *label;
int result;
if (mac_policy_count == 0)
return (1);
label = mac_mbuf_to_label(m);
result = 1;
MAC_POLICY_BOOLEAN_NOSLEEP(ipq_match, &&, m, label, q, q->ipq_label);
return (result);
}
void
mac_netinet_arp_send(struct ifnet *ifp, struct mbuf *m)
{
struct label *mlabel;
int locked;
if (mac_policy_count == 0)
return;
mlabel = mac_mbuf_to_label(m);
MAC_IFNET_LOCK(ifp, locked);
MAC_POLICY_PERFORM_NOSLEEP(netinet_arp_send, ifp, ifp->if_label, m,
mlabel);
MAC_IFNET_UNLOCK(ifp, locked);
}
void
mac_netinet_icmp_reply(struct mbuf *mrecv, struct mbuf *msend)
{
struct label *mrecvlabel, *msendlabel;
if (mac_policy_count == 0)
return;
mrecvlabel = mac_mbuf_to_label(mrecv);
msendlabel = mac_mbuf_to_label(msend);
MAC_POLICY_PERFORM_NOSLEEP(netinet_icmp_reply, mrecv, mrecvlabel,
msend, msendlabel);
}
void
mac_netinet_icmp_replyinplace(struct mbuf *m)
{
struct label *label;
if (mac_policy_count == 0)
return;
label = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(netinet_icmp_replyinplace, m, label);
}
void
mac_netinet_igmp_send(struct ifnet *ifp, struct mbuf *m)
{
struct label *mlabel;
int locked;
if (mac_policy_count == 0)
return;
mlabel = mac_mbuf_to_label(m);
MAC_IFNET_LOCK(ifp, locked);
MAC_POLICY_PERFORM_NOSLEEP(netinet_igmp_send, ifp, ifp->if_label, m,
mlabel);
MAC_IFNET_UNLOCK(ifp, locked);
}
void
mac_netinet_tcp_reply(struct mbuf *m)
{
struct label *label;
if (mac_policy_count == 0)
return;
label = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(netinet_tcp_reply, m, label);
}
void
mac_ipq_update(struct mbuf *m, struct ipq *q)
{
struct label *label;
if (mac_policy_count == 0)
return;
label = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(ipq_update, m, label, q, q->ipq_label);
}
MAC_CHECK_PROBE_DEFINE2(inpcb_check_deliver, "struct inpcb *",
"struct mbuf *");
int
mac_inpcb_check_deliver(struct inpcb *inp, struct mbuf *m)
{
struct label *label;
int error;
M_ASSERTPKTHDR(m);
if (mac_policy_count == 0)
return (0);
label = mac_mbuf_to_label(m);
MAC_POLICY_CHECK_NOSLEEP(inpcb_check_deliver, inp, inp->inp_label, m,
label);
MAC_CHECK_PROBE2(inpcb_check_deliver, error, inp, m);
return (error);
}
MAC_CHECK_PROBE_DEFINE2(inpcb_check_visible, "struct ucred *",
"struct inpcb *");
int
mac_inpcb_check_visible(struct ucred *cred, struct inpcb *inp)
{
int error;
INP_LOCK_ASSERT(inp);
MAC_POLICY_CHECK_NOSLEEP(inpcb_check_visible, cred, inp,
inp->inp_label);
MAC_CHECK_PROBE2(inpcb_check_visible, error, cred, inp);
return (error);
}
void
mac_inpcb_sosetlabel(struct socket *so, struct inpcb *inp)
{
INP_WLOCK_ASSERT(inp);
SOCK_LOCK_ASSERT(so);
MAC_POLICY_PERFORM_NOSLEEP(inpcb_sosetlabel, so, so->so_label, inp,
inp->inp_label);
}
void
mac_netinet_firewall_reply(struct mbuf *mrecv, struct mbuf *msend)
{
struct label *mrecvlabel, *msendlabel;
M_ASSERTPKTHDR(mrecv);
M_ASSERTPKTHDR(msend);
if (mac_policy_count == 0)
return;
mrecvlabel = mac_mbuf_to_label(mrecv);
msendlabel = mac_mbuf_to_label(msend);
MAC_POLICY_PERFORM_NOSLEEP(netinet_firewall_reply, mrecv, mrecvlabel,
msend, msendlabel);
}
void
mac_netinet_firewall_send(struct mbuf *m)
{
struct label *label;
M_ASSERTPKTHDR(m);
if (mac_policy_count == 0)
return;
label = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(netinet_firewall_send, m, label);
}
/*
* These functions really should be referencing the syncache structure
* instead of the label. However, due to some of the complexities associated
* with exposing this syncache structure we operate directly on its label
* pointer. This should be OK since we aren't making any access control
* decisions within this code directly, we are merely allocating and copying
* label storage so we can properly initialize mbuf labels for any packets
* the syncache code might create.
*/
void
mac_syncache_destroy(struct label **label)
{
if (*label != NULL) {
MAC_POLICY_PERFORM_NOSLEEP(syncache_destroy_label, *label);
mac_labelzone_free(*label);
*label = NULL;
}
}
int
mac_syncache_init(struct label **label)
{
int error;
if (mac_labeled & MPC_OBJECT_SYNCACHE) {
*label = mac_labelzone_alloc(M_NOWAIT);
if (*label == NULL)
return (ENOMEM);
/*
* Since we are holding the inpcb locks the policy can not
* allocate policy specific label storage using M_WAITOK. So
* we need to do a MAC_CHECK instead of the typical
* MAC_PERFORM so we can propagate allocation failures back
* to the syncache code.
*/
MAC_POLICY_CHECK_NOSLEEP(syncache_init_label, *label,
M_NOWAIT);
if (error) {
MAC_POLICY_PERFORM_NOSLEEP(syncache_destroy_label,
*label);
mac_labelzone_free(*label);
}
return (error);
} else
*label = NULL;
return (0);
}
void
mac_syncache_create(struct label *label, struct inpcb *inp)
{
INP_WLOCK_ASSERT(inp);
MAC_POLICY_PERFORM_NOSLEEP(syncache_create, label, inp);
}
void
mac_syncache_create_mbuf(struct label *sc_label, struct mbuf *m)
{
struct label *mlabel;
M_ASSERTPKTHDR(m);
if (mac_policy_count == 0)
return;
mlabel = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(syncache_create_mbuf, sc_label, m,
mlabel);
}