Commit Graph

91 Commits

Author SHA1 Message Date
Gleb Smirnoff
a68cc38879 Mechanical cleanup of epoch(9) usage in network stack.
- Remove macros that covertly create epoch_tracker on thread stack. Such
  macros a quite unsafe, e.g. will produce a buggy code if same macro is
  used in embedded scopes. Explicitly declare epoch_tracker always.

- Unmask interface list IFNET_RLOCK_NOSLEEP(), interface address list
  IF_ADDR_RLOCK() and interface AF specific data IF_AFDATA_RLOCK() read
  locking macros to what they actually are - the net_epoch.
  Keeping them as is is very misleading. They all are named FOO_RLOCK(),
  while they no longer have lock semantics. Now they allow recursion and
  what's more important they now no longer guarantee protection against
  their companion WLOCK macros.
  Note: INP_HASH_RLOCK() has same problems, but not touched by this commit.

This is non functional mechanical change. The only functionally changed
functions are ni6_addrs() and ni6_store_addrs(), where we no longer enter
epoch recursively.

Discussed with:	jtl, gallatin
2019-01-09 01:11:19 +00:00
Matt Macy
f9be038601 Fix in6_multi double free
This is actually several different bugs:
- The code is not designed to handle inpcb deletion after interface deletion
  - add reference for inpcb membership
- The multicast address has to be removed from interface lists when the refcount
  goes to zero OR when the interface goes away
  - decouple list disconnect from refcount (v6 only for now)
- ifmultiaddr can exist past being on interface lists
  - add flag for tracking whether or not it's enqueued
- deferring freeing moptions makes the incpb cleanup code simpler but opens the
  door wider still to races
  - call inp_gcmoptions synchronously after dropping the the inpcb lock

Fundamentally multicast needs a rewrite - but keep applying band-aids for now.

Tested by: kp
Reported by: novel, kp, lwhsu
2018-08-15 20:23:08 +00:00
Matt Macy
0f8d79d977 CK: update consumers to use CK macros across the board
r334189 changed the fields to have names distinct from those in queue.h
in order to expose the oversights as compile time errors
2018-05-24 23:21:23 +00:00
Matt Macy
cb6bb2303e ip(6)_freemoptions: defer imo destruction to epoch callback task
Avoid the ugly unlock / lock of the inpcbinfo where we need to
figure out what kind of lock we hold by simply deferring the
operation to another context. (Also a small dependency for
converting the pcbinfo read lock to epoch)
2018-05-20 00:22:28 +00:00
Matt Macy
d7c5a620e2 ifnet: Replace if_addr_lock rwlock with epoch + mutex
Run on LLNW canaries and tested by pho@

gallatin:
Using a 14-core, 28-HTT single socket E5-2697 v3 with a 40GbE MLX5
based ConnectX 4-LX NIC, I see an almost 12% improvement in received
packet rate, and a larger improvement in bytes delivered all the way
to userspace.

When the host receiving 64 streams of netperf -H $DUT -t UDP_STREAM -- -m 1,
I see, using nstat -I mce0 1 before the patch:

InMpps OMpps  InGbs  OGbs err TCP Est %CPU syscalls csw     irq GBfree
4.98   0.00   4.42   0.00 4235592     33   83.80 4720653 2149771   1235 247.32
4.73   0.00   4.20   0.00 4025260     33   82.99 4724900 2139833   1204 247.32
4.72   0.00   4.20   0.00 4035252     33   82.14 4719162 2132023   1264 247.32
4.71   0.00   4.21   0.00 4073206     33   83.68 4744973 2123317   1347 247.32
4.72   0.00   4.21   0.00 4061118     33   80.82 4713615 2188091   1490 247.32
4.72   0.00   4.21   0.00 4051675     33   85.29 4727399 2109011   1205 247.32
4.73   0.00   4.21   0.00 4039056     33   84.65 4724735 2102603   1053 247.32

After the patch

InMpps OMpps  InGbs  OGbs err TCP Est %CPU syscalls csw     irq GBfree
5.43   0.00   4.20   0.00 3313143     33   84.96 5434214 1900162   2656 245.51
5.43   0.00   4.20   0.00 3308527     33   85.24 5439695 1809382   2521 245.51
5.42   0.00   4.19   0.00 3316778     33   87.54 5416028 1805835   2256 245.51
5.42   0.00   4.19   0.00 3317673     33   90.44 5426044 1763056   2332 245.51
5.42   0.00   4.19   0.00 3314839     33   88.11 5435732 1792218   2499 245.52
5.44   0.00   4.19   0.00 3293228     33   91.84 5426301 1668597   2121 245.52

Similarly, netperf reports 230Mb/s before the patch, and 270Mb/s after the patch

Reviewed by:	gallatin
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D15366
2018-05-18 20:13:34 +00:00
Matt Macy
b6f6f88018 r333175 introduced deferred deletion of multicast addresses in order to permit the driver ioctl
to sleep on commands to the NIC when updating multicast filters. More generally this permitted
driver's to use an sx as a softc lock. Unfortunately this change introduced a race whereby a
a multicast update would still be queued for deletion when ifconfig deleted the interface
thus calling down in to _purgemaddrs and synchronously deleting _all_ of the multicast addresses
on the interface.

Synchronously remove all external references to a multicast address before enqueueing for delete.

Reported by:	lwhsu
Approved by:	sbruno
2018-05-06 20:34:13 +00:00
Matt Macy
28c001002a Currently in_pcbfree will unconditionally wunlock the pcbinfo lock
to avoid a LOR on the multicast list lock in the freemoptions routines.
As it turns out, tcp_usr_detach can acquire the tcbinfo lock readonly.
Trying to wunlock the pcbinfo lock in that context has caused a number
of reported crashes.

This change unclutters in_pcbfree and moves the handling of wunlock vs
runlock of pcbinfo to the freemoptions routine.

Reported by:	mjg@, bde@, o.hartmann at walstatt.org
Approved by:	sbruno
2018-05-05 22:40:40 +00:00
Stephen Hurd
f3e1324b41 Separate list manipulation locking from state change in multicast
Multicast incorrectly calls in to drivers with a mutex held causing drivers
to have to go through all manner of contortions to use a non sleepable lock.
Serialize multicast updates instead.

Submitted by:	mmacy <mmacy@mattmacy.io>
Reviewed by:	shurd, sbruno
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D14969
2018-05-02 19:36:29 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00
Andrey V. Elsukov
5a1842a24a Add ip6_tryforward() - a run to completion forwarding implementation
for IPv6.

It gets performance benefits from reduced number of checks. It doesn't
copy mbuf to be able send ICMPv6 error message, because it keeps mbuf
unchanged until the moment, when the route decision has been made.
It doesn't do IPsec checks, and when some IPsec security policies present,
ip6_input() uses normal slow path.

Reviewed by:	bz, gnn
Obtained from:	Yandex LLC
MFC after:	1 month
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D8527
2016-12-12 10:57:32 +00:00
Pedro F. Giffuni
268aab1cfc Remove the SIOCSIFALIFETIME_IN6 ioctl.
The SIOCSIFALIFETIME_IN6 provided by the kame project is unused,
it can't really be used safely and has been completely removed from
NetBSD and OpenBSD.

Obtained from:	NetBSD (kern/35897)
PR:		210148 (exp-run)
Reviewed by:	ae, hrs
Relnotes:	yes
Approved by:	re (glebius)
Differential Revision:	https://reviews.freebsd.org/D5491
2016-06-13 22:31:16 +00:00
Steven Hartland
d6e82913c1 Revert r292275 & r292379
glebius has concerns about these changes so reverting those can be discussed
and addressed.

Sponsored by:	Multiplay
2015-12-17 14:41:30 +00:00
Steven Hartland
52e53e2de0 Fix lagg failover due to missing notifications
When using lagg failover mode neither Gratuitous ARP (IPv4) or Unsolicited
Neighbour Advertisements (IPv6) are sent to notify other nodes that the
address may have moved.

This results is slow failover, dropped packets and network outages for the
lagg interface when the primary link goes down.

We now use the new if_link_state_change_cond with the force param set to
allow lagg to force through link state changes and hence fire a
ifnet_link_event which are now monitored by rip and nd6.

Upon receiving these events each protocol trigger the relevant
notifications:
* inet4 => Gratuitous ARP
* inet6 => Unsolicited Neighbour Announce

This also fixes the carp IPv6 NA's that stopped working after r251584 which
added the ipv6_route__llma route.

The new behavour can be controlled using the sysctls:
* net.link.ether.inet.arp_on_link
* net.inet6.icmp6.nd6_on_link

Also removed unused param from lagg_port_state and added descriptions for the
sysctls while here.

PR:		156226
MFC after:	1 month
Sponsored by:	Multiplay
Differential Revision:	https://reviews.freebsd.org/D4111
2015-12-15 16:02:11 +00:00
Hiroki Sato
e3884653f6 - Remove SIOCGDRLST_IN6 and SIOCGPRLST_IN6. These are quite old APIs and
there is no consumer now.

MFC after:	3 days
2015-09-10 06:31:24 +00:00
Hiroki Sato
3ba7e4ce9c Remove IN6_IFF_NOPFX. This flag was no longer used.
MFC after:	3 days
2015-09-10 06:08:42 +00:00
Alexander V. Chernikov
91bfd68e38 Make in6ifa_ifpwithaddr() take const param.
Remove unneded DECONST from in6_lltable_rtcheck().
2015-09-05 05:54:09 +00:00
Hiroki Sato
fb583bd228 - Deprecate IN6_IFF_NODAD. It was used to prevent DAD on a loopback
interface but in6if_do_dad() already had a check for IFF_LOOPBACK.

- Remove in6if_do_dad() check in in6_broadcast_ifa().  An address
  which needs DAD always has IN6_IFF_TENTATIVE there.

- in6if_do_dad() now returns EAGAIN when the interface is not ready
  since DAD callout handler ignores such an interface.

- In DAD callout handler, mark an address as IN6_IFF_TENTATIVE
  when the interface has ND6_IFF_IFDISABLED.  And Do IFF_UP and
  IFF_DRV_RUNNING check consistently when DAD is required.

- draft-ietf-6man-enhanced-dad is now published as RFC 7527.

- Fix some typos.
2015-08-24 05:21:49 +00:00
Andrey V. Elsukov
cc0a3c8ca4 Convert in_ifaddr_lock and in6_ifaddr_lock to rmlock.
Both are used to protect access to IP addresses lists and they can be
acquired for reading several times per packet. To reduce lock contention
it is better to use rmlock here.

Reviewed by:	gnn (previous version)
Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D3149
2015-07-29 08:12:05 +00:00
Gleb Smirnoff
20778ab5b4 Move ip6_sprintf() declaration from in6_var.h to in6.h. This is a simple
function that works with in6_addr and it is not related to the INET6
stack implementation.

Sponsored by:	Nginx, Inc.
2015-03-24 16:45:50 +00:00
Gleb Smirnoff
e072c794ad Now that all users of _WANT_IFADDR are fixed, remove this crutch and
hide ifaddr, in_ifaddr and in6_ifaddr under _KERNEL.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2015-02-19 23:16:10 +00:00
Gleb Smirnoff
9e62a5a379 - Rename 'struct mld_ifinfo' into 'struct mld_ifsoftc', since it really
represents a context.
- Preserve name 'struct mld_ifinfo' for a new structure, that will be stable
  API between userland and kernel.
- Make sysctl_mld_ifinfo() return the new 'struct mld_ifinfo', instead of
  old one, which had a bunch of internal kernel structures in it.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2015-02-19 22:37:01 +00:00
Gleb Smirnoff
fd1b2a7c57 Widen _KERNEL ifdef to hide more kernel network stack structures from userland. 2015-02-19 06:24:27 +00:00
Gleb Smirnoff
a99c84d4e6 Use new struct mbufq instead of struct ifqueue to manage packet queues in
IPv6 multicast code.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2015-02-19 01:21:23 +00:00
Alexander V. Chernikov
1a75e3b20f Make checks for rt_mtu generic:
Some virtual if drivers has (ab)used ifa ifa_rtrequest hook to enforce
route MTU to be not bigger that interface MTU. While ifa_rtrequest hooking
might be an option in some situation, it is not feasible to do MTU checks
there: generic (or per-domain) routing code is perfectly capable of doing
this.

We currrently have 3 places where MTU is altered:

1) route addition.
 In this case domain overrides radix _addroute callback (in[6]_addroute)
 and all necessary checks/fixes are/can be done there.

2) route change (especially, GW change).
 In this case, there are no explicit per-domain calls, but one can
 override rte by setting ifa_rtrequest hook to domain handler
 (inet6 does this).

3) ifconfig ifaceX mtu YYYY
 In this case, we have no callbacks, but ip[6]_output performes runtime
 checks and decreases rt_mtu if necessary.

Generally, the goals are to be able to handle all MTU changes in
 control plane, not in runtime part, and properly deal with increased
 interface MTU.

This commit changes the following:
* removes hooks setting MTU from drivers side
* adds proper per-doman MTU checks for case 1)
* adds generic MTU check for case 2)

* The latter is done by using new dom_ifmtu callback since
 if_mtu denotes L3 interface MTU, e.g. maximum trasmitted _packet_ size.
 However, IPv6 mtu might be different from if_mtu one (e.g. default 1280)
 for some cases, so we need an abstract way to know maximum MTU size
 for given interface and domain.
* moves rt_setmetrics() before MTU/ifa_rtrequest hooks since it copies
  user-supplied data which must be checked.
* removes RT_LOCK_ASSERT() from other ifa_rtrequest hooks to be able to
  use this functions on new non-inserted rte.

More changes will follow soon.

MFC after:	1 month
Sponsored by:	Yandex LLC
2014-11-06 13:13:09 +00:00
Andrey V. Elsukov
8e4bdfa2db Remove unused function.
Sponsored by:	Yandex LLC
2014-10-27 10:34:09 +00:00
Andrey V. Elsukov
343e440f63 Add const qualifier to in6_addrhash() function.
Add in6ifa_ifwithaddr() function. It is similar to ifa_ifwithaddr,
but does fast lookup in the hash of inet6 addresses.

Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC
2014-09-11 13:18:41 +00:00
Andrey V. Elsukov
5dbfa43f65 Add the ability to set `prefer_source' flag to an IPv6 address.
It affects the IPv6 source address selection algorithm (RFC 6724)
and allows override the last rule ("longest matching prefix") for
choosing among equivalent addresses. The address with `prefer_source'
will be preferred source address.

Obtained from:	Yandex LLC
MFC after:	1 month
Sponsored by:	Yandex LLC
2014-09-09 10:52:50 +00:00
Alexander V. Chernikov
f6b84910bb Further rework netinet6 address handling code:
* Set ia address/mask values BEFORE attaching to address lists.
Inet6 address assignment is not atomic, so the simplest way to
do this atomically is to fill in ia before attach.
* Validate irfa->ia_addr field before use (we permit ANY sockaddr in old code).
* Do some renamings:
  in6_ifinit -> in6_notify_ifa (interaction with other subsystems is here)
  in6_setup_ifa -> in6_broadcast_ifa (LLE/Multicast/DaD code)
  in6_ifaddloop -> nd6_add_ifa_lle
  in6_ifremloop -> nd6_rem_ifa_lle
* Split working with LLE and route announce code for last two.
Add temporary in6_newaddrmsg() function to mimic current rtsock behaviour.
* Call device SIOCSIFADDR handler IFF we're adding first address.
In IPv4 we have to call it on every address change since ARP record
is installed by arp_ifinit() which is called by given handler.
IPv6 stack, on the opposite is responsible to call nd6_add_ifa_lle() so
there is no reason to call SIOCSIFADDR often.
2014-01-19 16:07:27 +00:00
Alexander V. Chernikov
9080e7d023 Add in6_prepare_ifra() function to ease preparing in-kernel IPv6
address requests.

MFC after:	2 weeks
2014-01-18 20:32:59 +00:00
Alexander V. Chernikov
1dc8f6a82c Introduce IN6_MASK_ADDR() macro to unify various hand-rolled code
to do IPv6 addr & mask in different places.

MFC after:	2 weeks
2014-01-08 22:13:32 +00:00
Gleb Smirnoff
6ed910fabe Hide 'struct ifaddr' definition from userland. Two tools left that use it,
namely ipftest(1) and ifmcstat(1). These sniff structure definition using
_WANT_IFADDR define.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-15 10:19:24 +00:00
Gleb Smirnoff
0218539652 Now counter_u64_t is known to userland, thus remove hack from r253086.
Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-15 10:09:33 +00:00
Andrey V. Elsukov
2841260cd6 Migrate structs in6_ifstat and icmp6_ifstat to PCPU counters. 2013-07-09 09:59:46 +00:00
Andrey V. Elsukov
a786f67981 Migrate structs ip6stat, icmp6stat and rip6stat to PCPU counters. 2013-07-09 09:54:54 +00:00
Andrey V. Elsukov
c80211e3cf Prepare network statistics structures for migration to PCPU counters.
Use uint64_t as type for all fields of structures.

Changed structures: ahstat, arpstat, espstat, icmp6_ifstat, icmp6stat,
in6_ifstat, ip6stat, ipcompstat, ipipstat, ipsecstat, mrt6stat, mrtstat,
pfkeystat, pim6stat, pimstat, rip6stat, udpstat.

Discussed with:	arch@
2013-07-09 09:32:06 +00:00
Hiroki Sato
af8056441e - Allow ND6_IFF_AUTO_LINKLOCAL for IFT_BRIDGE. An interface with IFT_BRIDGE
is initialized with !ND6_IFF_AUTO_LINKLOCAL && !ND6_IFF_ACCEPT_RTADV
  regardless of net.inet6.ip6.accept_rtadv and net.inet6.ip6.auto_linklocal.
  To configure an autoconfigured link-local address (RFC 4862), the
  following rc.conf(5) configuration can be used:

   ifconfig_bridge0_ipv6="inet6 auto_linklocal"

- if_bridge(4) now removes IPv6 addresses on a member interface to be
  added when the parent interface or one of the existing member
  interfaces has an IPv6 address.  if_bridge(4) merges each link-local
  scope zone which the member interfaces form respectively, so it causes
  address scope violation.  Removal of the IPv6 addresses prevents it.

- if_lagg(4) now removes IPv6 addresses on a member interfaces
  unconditionally.

- Set reasonable flags to non-IPv6-capable interfaces. [*]

Submitted by:	rpaulo [*]
MFC after:	1 week
2013-07-02 16:58:15 +00:00
Andrey V. Elsukov
817f395375 Remove unused variable.
MFC after:	1 week
2013-04-24 10:24:01 +00:00
Andrey V. Elsukov
68eba526b9 In additional to the tailq of IPv6 addresses add the hash table.
For now use 256 buckets and fnv_hash function. Use xor'ed 32-bit
s6_addr32 parts of in6_addr structure as a hash key. Update
in6_localip and in6_is_addr_deprecated to use hash table for fastest
lookup.

Sponsored by:	Yandex LLC
Discussed with:	dwmalone, glebius, bz
2012-12-15 20:04:24 +00:00
Xin LI
6f56329a25 Remove __P.
Submitted by:	kevlo
Reviewed by:	md5(1)
MFC after:	2 months
2012-10-22 21:49:56 +00:00
Bjoern A. Zeeb
db566a23b6 Provide the IPv6 counterpart to the extended IPv4 rtalloc(9) KPI.
Sponsored by:	Cisco Systems, Inc.
2012-02-03 09:33:58 +00:00
John Baldwin
137f91e80f Convert all users of IF_ADDR_LOCK to use new locking macros that specify
either a read lock or write lock.

Reviewed by:	bz
MFC after:	2 weeks
2012-01-05 19:00:36 +00:00
Bjoern A. Zeeb
ad05fc1d2d Remove an uneeded inpcb forward declaration and align the function
declaration following to match the style in the rest of the file.

MFC after:	3 days
2012-01-02 13:03:13 +00:00
Gleb Smirnoff
7121247312 Provide ABI compatibility shim to enable configuring of addresses
with ifconfig(8) prior to r228571.

Requested by:	brooks
2011-12-21 12:39:08 +00:00
Gleb Smirnoff
08b68b0e4c A major overhaul of the CARP implementation. The ip_carp.c was started
from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.

The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.

ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.

To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]

The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.

Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!

PR:		kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by:	bz
Submitted by:	bz [1]
2011-12-16 12:16:56 +00:00
Bjoern A. Zeeb
82cea7e6f3 MFP4: @176978-176982, 176984, 176990-176994, 177441
"Whitspace" churn after the VIMAGE/VNET whirls.

Remove the need for some "init" functions within the network
stack, like pim6_init(), icmp_init() or significantly shorten
others like ip6_init() and nd6_init(), using static initialization
again where possible and formerly missed.

Move (most) variables back to the place they used to be before the
container structs and VIMAGE_GLOABLS (before r185088) and try to
reduce the diff to stable/7 and earlier as good as possible,
to help out-of-tree consumers to update from 6.x or 7.x to 8 or 9.

This also removes some header file pollution for putatively
static global variables.

Revert VIMAGE specific changes in ipfilter::ip_auth.c, that are
no longer needed.

Reviewed by:	jhb
Discussed with:	rwatson
Sponsored by:	The FreeBSD Foundation
Sponsored by:	CK Software GmbH
MFC after:	6 days
2010-04-29 11:52:42 +00:00
Robert Watson
1e77c1056a Remove unused VNET_SET() and related macros; only VNET_GET() is
ever actually used.  Rename VNET_GET() to VNET() to shorten
variable references.

Discussed with:	bz, julian
Reviewed by:	bz
Approved by:	re (kensmith, kib)
2009-07-16 21:13:04 +00:00
Robert Watson
eddfbb763d Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)
2009-07-14 22:48:30 +00:00
Robert Watson
5f06a81ae9 Fix "options VIMAGE_GLOBALS" build following introduction of
in6_ifaddrhead.

Approved by:	re (kib)
2009-06-29 15:23:50 +00:00
Robert Watson
d1da0a0672 Add address list locking for in6_ifaddrhead/ia_link: as with locking
for in_ifaddrhead, we stick with an rwlock for the time being, which
we will revisit in the future with a possible move to rmlocks.

Some pieces of code require significant further reworking to be
safe from all classes of writer-writer races.

Reviewed by:	bz
MFC after:	6 weeks
2009-06-25 16:35:28 +00:00