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author | bms <bms@FreeBSD.org> | 2009-04-29 19:19:13 +0000 |
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committer | bms <bms@FreeBSD.org> | 2009-04-29 19:19:13 +0000 |
commit | 32a71137f08bc028578417de36a241d7e6011f58 (patch) | |
tree | 51d9a006ee48417962ce45f044b7e5603910fe13 /UPDATING | |
parent | 51a4d1c4a3d279a3638c0b40f351aa93f965c7df (diff) | |
download | FreeBSD-src-32a71137f08bc028578417de36a241d7e6011f58.zip FreeBSD-src-32a71137f08bc028578417de36a241d7e6011f58.tar.gz |
Bite the bullet, and make the IPv6 SSM and MLDv2 mega-commit:
import from p4 bms_netdev. Summary of changes:
* Connect netinet6/in6_mcast.c to build.
The legacy KAME KPIs are mostly preserved.
* Eliminate now dead code from ip6_output.c.
Don't do mbuf bingo, we are not going to do RFC 2292 style
CMSG tricks for multicast options as they are not required
by any current IPv6 normative reference.
* Refactor transports (UDP, raw_ip6) to do own mcast filtering.
SCTP, TCP unaffected by this change.
* Add ip6_msource, in6_msource structs to in6_var.h.
* Hookup mld_ifinfo state to in6_ifextra, allocate from
domifattach path.
* Eliminate IN6_LOOKUP_MULTI(), it is no longer referenced.
Kernel consumers which need this should use in6m_lookup().
* Refactor IPv6 socket group memberships to use a vector (like IPv4).
* Update ifmcstat(8) for IPv6 SSM.
* Add witness lock order for IN6_MULTI_LOCK.
* Move IN6_MULTI_LOCK out of lower ip6_output()/ip6_input() paths.
* Introduce IP6STAT_ADD/SUB/INC/DEC as per rwatson's IPv4 cleanup.
* Update carp(4) for new IPv6 SSM KPIs.
* Virtualize ip6_mrouter socket.
Changes mostly localized to IPv6 MROUTING.
* Don't do a local group lookup in MROUTING.
* Kill unused KAME prototypes in6_purgemkludge(), in6_restoremkludge().
* Preserve KAME DAD timer jitter behaviour in MLDv1 compatibility mode.
* Bump __FreeBSD_version to 800084.
* Update UPDATING.
NOTE WELL:
* This code hasn't been tested against real MLDv2 queriers
(yet), although the on-wire protocol has been verified in Wireshark.
* There are a few unresolved issues in the socket layer APIs to
do with scope ID propagation.
* There is a LOR present in ip6_output()'s use of
in6_setscope() which needs to be resolved. See comments in mld6.c.
This is believed to be benign and can't be avoided for the moment
without re-introducing an indirect netisr.
This work was mostly derived from the IGMPv3 implementation, and
has been sponsored by a third party.
Diffstat (limited to 'UPDATING')
-rw-r--r-- | UPDATING | 86 |
1 files changed, 86 insertions, 0 deletions
@@ -22,6 +22,92 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 8.x IS SLOW: to maximize performance. (To disable malloc debugging, run ln -s aj /etc/malloc.conf.) +20090429: + MLDv2 and Source-Specific Multicast (SSM) have been merged + to the IPv6 stack. VIMAGE hooks are in but not yet used. + The implementation of SSM within FreeBSD's IPv6 stack closely + follows the IPv4 implementation. + + For kernel developers: + + * The most important changes are that the ip6_output() and + ip6_input() paths no longer take the IN6_MULTI_LOCK, + and this lock has been downgraded to a non-recursive mutex. + + * As with the changes to the IPv4 stack to support SSM, filtering + of inbound multicast traffic must now be performed by transport + protocols within the IPv6 stack. This does not apply to TCP and + SCTP, however, it does apply to UDP in IPv6 and raw IPv6. + + * The KPIs used by IPv6 multicast are similar to those used by + the IPv4 stack, with the following differences: + * im6o_mc_filter() is analogous to imo_multicast_filter(). + * The legacy KAME entry points in6_joingroup and in6_leavegroup() + are shimmed to in6_mc_join() and in6_mc_leave() respectively. + * IN6_LOOKUP_MULTI() has been deprecated and removed. + * IPv6 relies on MLD for the DAD mechanism. KAME's internal KPIs + for MLDv1 have an additional 'timer' argument which is used to + jitter the initial membership report for the solicited-node + multicast membership on-link. + * This is not strictly needed for MLDv2, which already jitters + its report transmissions. However, the 'timer' argument is + preserved in case MLDv1 is active on the interface. + + * The KAME linked-list based IPv6 membership implementation has + been refactored to use a vector similar to that used by the IPv4 + stack. + Code which maintains a list of its own multicast memberships + internally, e.g. carp, has been updated to reflect the new + semantics. + + * There is a known Lock Order Reversal (LOR) due to in6_setscope() + acquiring the IF_AFDATA_LOCK and being called within ip6_output(). + Whilst MLDv2 tries to avoid this otherwise benign LOR, it is an + implementation constraint which needs to be addressed in HEAD. + + For application developers: + + * The changes are broadly similar to those made for the IPv4 + stack. + + * The use of IPv4 and IPv6 multicast socket options on the same + socket, using mapped addresses, HAS NOT been tested or supported. + + * There are a number of issues with the implementation of various + IPv6 multicast APIs which need to be resolved in the API surface + before the implementation is fully compatible with KAME userland + use, and these are mostly to do with interface index treatment. + + * The literature available discusses the use of either the delta / ASM + API with setsockopt(2)/getsockopt(2), or the full-state / ASM API + using setsourcefilter(3)/getsourcefilter(3). For more information + please refer to RFC 3768, 'Socket Interface Extensions for + Multicast Source Filters'. + + * Applications which use the published RFC 3678 APIs should be fine. + + For systems administrators: + + * The mtest(8) utility has been refactored to support IPv6, in + addition to IPv4. Interface addresses are no longer accepted + as arguments, their names must be used instead. The utility + will map the interface name to its first IPv4 address as + returned by getifaddrs(3). + + * The ifmcstat(8) utility has also been updated to print the MLDv2 + endpoint state and source filter lists via sysctl(3). + + * The net.inet6.ip6.mcast.loop sysctl may be tuned to 0 to disable + loopback of IPv6 multicast datagrams by default; it defaults to 1 + to preserve the existing behaviour. Disabling multicast loopback is + recommended for optimal system performance. + + * The IPv6 MROUTING code has been changed to examine this sysctl + instead of attempting to perform a group lookup before looping + back forwarded datagrams. + + Bump __FreeBSD_version to 800084. + 20090422: Implement low-level Bluetooth HCI API. Bump __FreeBSD_version to 800083. |