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freebsd/sys/netinet6/mld6_var.h
Hans Petter Selasky 2cd6ad766e Fix refcounting leaks in IPv6 MLD code leading to loss of IPv6
connectivity.

Looking at past changes in this area like r337866, some refcounting
bugs have been introduced, one by one. For example like calling
in6m_disconnect() and in6m_rele_locked() in mld_v1_process_group_timer()
where previously no disconnect nor refcount decrement was done.
Calling in6m_disconnect() when it shouldn't causes IPv6 solitation to no
longer work, because all the multicast addresses receiving the solitation
messages are now deleted from the network interface.

This patch reverts some recent changes while improving the MLD
refcounting and concurrency model after the MLD code was converted
to using EPOCH(9).

List changes:
- All CK_STAILQ_FOREACH() macros are now properly enclosed into
  EPOCH(9) sections. This simplifies assertion of locking inside
  in6m_ifmultiaddr_get_inm().
- Corrected bad use of in6m_disconnect() leading to loss of IPv6
  connectivity for MLD v1.
- Factored out checks for valid inm structure into
  in6m_ifmultiaddr_get_inm().

PR:			233535
Differential Revision:	https://reviews.freebsd.org/D18887
Reviewed by:		bz (net)
Tested by:		ae
MFC after:		1 week
Sponsored by:		Mellanox Technologies
2019-01-24 08:34:13 +00:00

180 lines
6.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2009 Bruce Simpson.
*
* 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.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* 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 _NETINET6_MLD6_VAR_H_
#define _NETINET6_MLD6_VAR_H_
/*
* Multicast Listener Discovery (MLD)
* implementation-specific definitions.
*/
/*
* MLD per-group states.
*/
#define MLD_NOT_MEMBER 0 /* Can garbage collect group */
#define MLD_SILENT_MEMBER 1 /* Do not perform MLD for group */
#define MLD_REPORTING_MEMBER 2 /* MLDv1 we are reporter */
#define MLD_IDLE_MEMBER 3 /* MLDv1 we reported last */
#define MLD_LAZY_MEMBER 4 /* MLDv1 other member reporting */
#define MLD_SLEEPING_MEMBER 5 /* MLDv1 start query response */
#define MLD_AWAKENING_MEMBER 6 /* MLDv1 group timer will start */
#define MLD_G_QUERY_PENDING_MEMBER 7 /* MLDv2 group query pending */
#define MLD_SG_QUERY_PENDING_MEMBER 8 /* MLDv2 source query pending */
#define MLD_LEAVING_MEMBER 9 /* MLDv2 dying gasp (pending last */
/* retransmission of INCLUDE {}) */
/*
* MLD version tag.
*/
#define MLD_VERSION_NONE 0 /* Invalid */
#define MLD_VERSION_1 1
#define MLD_VERSION_2 2 /* Default */
/*
* MLDv2 protocol control variables.
*/
#define MLD_RV_INIT 2 /* Robustness Variable */
#define MLD_RV_MIN 1
#define MLD_RV_MAX 7
#define MLD_QI_INIT 125 /* Query Interval (s) */
#define MLD_QI_MIN 1
#define MLD_QI_MAX 255
#define MLD_QRI_INIT 10 /* Query Response Interval (s) */
#define MLD_QRI_MIN 1
#define MLD_QRI_MAX 255
#define MLD_URI_INIT 3 /* Unsolicited Report Interval (s) */
#define MLD_URI_MIN 0
#define MLD_URI_MAX 10
#define MLD_MAX_GS_SOURCES 256 /* # of sources in rx GS query */
#define MLD_MAX_G_GS_PACKETS 8 /* # of packets to answer G/GS */
#define MLD_MAX_STATE_CHANGE_PACKETS 8 /* # of packets per state change */
#define MLD_MAX_RESPONSE_PACKETS 16 /* # of packets for general query */
#define MLD_MAX_RESPONSE_BURST 4 /* # of responses to send at once */
#define MLD_RESPONSE_BURST_INTERVAL (PR_FASTHZ / 2) /* 500ms */
/*
* MLD-specific mbuf flags.
*/
#define M_MLDV1 M_PROTO1 /* Packet is MLDv1 */
#define M_GROUPREC M_PROTO3 /* mbuf chain is a group record */
/*
* Leading space for MLDv2 reports inside MTU.
*
* NOTE: This differs from IGMPv3 significantly. KAME IPv6 requires
* that a fully formed mbuf chain *without* the Router Alert option
* is passed to ip6_output(), however we must account for it in the
* MTU if we need to split an MLDv2 report into several packets.
*
* We now put the MLDv2 report header in the initial mbuf containing
* the IPv6 header.
*/
#define MLD_MTUSPACE (sizeof(struct ip6_hdr) + sizeof(struct mld_raopt) + \
sizeof(struct icmp6_hdr))
/*
* Structure returned by net.inet6.mld.ifinfo.
*/
struct mld_ifinfo {
uint32_t mli_version; /* MLDv1 Host Compatibility Mode */
uint32_t mli_v1_timer; /* MLDv1 Querier Present timer (s) */
uint32_t mli_v2_timer; /* MLDv2 General Query (interface) timer (s)*/
uint32_t mli_flags; /* MLD per-interface flags */
#define MLIF_SILENT 0x00000001 /* Do not use MLD on this ifp */
#define MLIF_USEALLOW 0x00000002 /* Use ALLOW/BLOCK for joins/leaves */
uint32_t mli_rv; /* MLDv2 Robustness Variable */
uint32_t mli_qi; /* MLDv2 Query Interval (s) */
uint32_t mli_qri; /* MLDv2 Query Response Interval (s) */
uint32_t mli_uri; /* MLDv2 Unsolicited Report Interval (s) */
};
#ifdef _KERNEL
/*
* Per-link MLD state.
*/
struct mld_ifsoftc {
LIST_ENTRY(mld_ifsoftc) mli_link;
struct ifnet *mli_ifp; /* interface this instance belongs to */
uint32_t mli_version; /* MLDv1 Host Compatibility Mode */
uint32_t mli_v1_timer; /* MLDv1 Querier Present timer (s) */
uint32_t mli_v2_timer; /* MLDv2 General Query (interface) timer (s)*/
uint32_t mli_flags; /* MLD per-interface flags */
uint32_t mli_rv; /* MLDv2 Robustness Variable */
uint32_t mli_qi; /* MLDv2 Query Interval (s) */
uint32_t mli_qri; /* MLDv2 Query Response Interval (s) */
uint32_t mli_uri; /* MLDv2 Unsolicited Report Interval (s) */
struct mbufq mli_gq; /* queue of general query responses */
};
#define MLD_RANDOM_DELAY(X) (arc4random() % (X) + 1)
#define MLD_MAX_STATE_CHANGES 24 /* Max pending changes per group */
/*
* Subsystem lock macros.
* The MLD lock is only taken with MLD. Currently it is system-wide.
* VIMAGE: The lock could be pushed to per-VIMAGE granularity in future.
*/
#define MLD_LOCK_INIT() mtx_init(&mld_mtx, "mld_mtx", NULL, MTX_DEF)
#define MLD_LOCK_DESTROY() mtx_destroy(&mld_mtx)
#define MLD_LOCK() mtx_lock(&mld_mtx)
#define MLD_LOCK_ASSERT() mtx_assert(&mld_mtx, MA_OWNED)
#define MLD_UNLOCK() mtx_unlock(&mld_mtx)
#define MLD_UNLOCK_ASSERT() mtx_assert(&mld_mtx, MA_NOTOWNED)
/*
* Per-link MLD context.
*/
#define MLD_IFINFO(ifp) \
(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->mld_ifinfo)
struct in6_multi_head;
int mld_change_state(struct in6_multi *, const int);
struct mld_ifsoftc *
mld_domifattach(struct ifnet *);
void mld_domifdetach(struct ifnet *);
void mld_fasttimo(void);
void mld_ifdetach(struct ifnet *, struct in6_multi_head *);
int mld_input(struct mbuf *, int, int);
void mld_slowtimo(void);
#ifdef SYSCTL_DECL
SYSCTL_DECL(_net_inet6_mld);
#endif
#endif /* _KERNEL */
#endif /* _NETINET6_MLD6_VAR_H_ */