unsynchronized. While races were extremely rare, we've now had a
couple of reports of panics in environments involving large numbers of
IPSEC tunnels being added very quickly on an active system.
- Add accessor functions ifnet_byindex(), ifaddr_byindex(),
ifdev_byindex() to replace existing accessor macros. These functions
now acquire the ifnet lock before derefencing the table.
- Add IFNET_WLOCK_ASSERT().
- Add static accessor functions ifnet_setbyindex(), ifdev_setbyindex(),
which set values in the table either asserting of acquiring the ifnet
lock.
- Use accessor functions throughout if.c to modify and read
ifindex_table.
- Rework ifnet attach/detach to lock around ifindex_table modification.
Note that these changes simply close races around use of ifindex_table,
and make no attempt to solve the probem of disappearing ifnets. Further
refinement of this work, including with respect to ifindex_table
resizing, is still required.
In a future change, the ifnet lock should be converted from a mutex to an
rwlock in order to reduce contention.
Reviewed and tested by: brooks
- verified that the ifp->if_snd.ifq_mtx was initalized for
all attached interfaces. This was pointless because it was
initalized for all interfaces in if_attach() so I've removed it.
- Checked that ifp->if_snd.ifq_maxlen is initalized and set it to
ifqmaxlen if unset. This makes more sense in if_attach() so
I moved it there.
- The first call of if_slowtimo(). Delete if_check() and call
if_slowtimo() directly from the SYSINIT().
This particular implementation is designed to be fully backwards compatible
and to be MFC-able to 7.x (and 6.x)
Currently the only protocol that can make use of the multiple tables is IPv4
Similar functionality exists in OpenBSD and Linux.
From my notes:
-----
One thing where FreeBSD has been falling behind, and which by chance I
have some time to work on is "policy based routing", which allows
different
packet streams to be routed by more than just the destination address.
Constraints:
------------
I want to make some form of this available in the 6.x tree
(and by extension 7.x) , but FreeBSD in general needs it so I might as
well do it in -current and back port the portions I need.
One of the ways that this can be done is to have the ability to
instantiate multiple kernel routing tables (which I will now
refer to as "Forwarding Information Bases" or "FIBs" for political
correctness reasons). Which FIB a particular packet uses to make
the next hop decision can be decided by a number of mechanisms.
The policies these mechanisms implement are the "Policies" referred
to in "Policy based routing".
One of the constraints I have if I try to back port this work to
6.x is that it must be implemented as a EXTENSION to the existing
ABIs in 6.x so that third party applications do not need to be
recompiled in timespan of the branch.
This first version will not have some of the bells and whistles that
will come with later versions. It will, for example, be limited to 16
tables in the first commit.
Implementation method, Compatible version. (part 1)
-------------------------------
For this reason I have implemented a "sufficient subset" of a
multiple routing table solution in Perforce, and back-ported it
to 6.x. (also in Perforce though not always caught up with what I
have done in -current/P4). The subset allows a number of FIBs
to be defined at compile time (8 is sufficient for my purposes in 6.x)
and implements the changes needed to allow IPV4 to use them. I have not
done the changes for ipv6 simply because I do not need it, and I do not
have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it.
Other protocol families are left untouched and should there be
users with proprietary protocol families, they should continue to work
and be oblivious to the existence of the extra FIBs.
To understand how this is done, one must know that the current FIB
code starts everything off with a single dimensional array of
pointers to FIB head structures (One per protocol family), each of
which in turn points to the trie of routes available to that family.
The basic change in the ABI compatible version of the change is to
extent that array to be a 2 dimensional array, so that
instead of protocol family X looking at rt_tables[X] for the
table it needs, it looks at rt_tables[Y][X] when for all
protocol families except ipv4 Y is always 0.
Code that is unaware of the change always just sees the first row
of the table, which of course looks just like the one dimensional
array that existed before.
The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign()
are all maintained, but refer only to the first row of the array,
so that existing callers in proprietary protocols can continue to
do the "right thing".
Some new entry points are added, for the exclusive use of ipv4 code
called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(),
which have an extra argument which refers the code to the correct row.
In addition, there are some new entry points (currently called
rtalloc_fib() and friends) that check the Address family being
looked up and call either rtalloc() (and friends) if the protocol
is not IPv4 forcing the action to row 0 or to the appropriate row
if it IS IPv4 (and that info is available). These are for calling
from code that is not specific to any particular protocol. The way
these are implemented would change in the non ABI preserving code
to be added later.
One feature of the first version of the code is that for ipv4,
the interface routes show up automatically on all the FIBs, so
that no matter what FIB you select you always have the basic
direct attached hosts available to you. (rtinit() does this
automatically).
You CAN delete an interface route from one FIB should you want
to but by default it's there. ARP information is also available
in each FIB. It's assumed that the same machine would have the
same MAC address, regardless of which FIB you are using to get
to it.
This brings us as to how the correct FIB is selected for an outgoing
IPV4 packet.
Firstly, all packets have a FIB associated with them. if nothing
has been done to change it, it will be FIB 0. The FIB is changed
in the following ways.
Packets fall into one of a number of classes.
1/ locally generated packets, coming from a socket/PCB.
Such packets select a FIB from a number associated with the
socket/PCB. This in turn is inherited from the process,
but can be changed by a socket option. The process in turn
inherits it on fork. I have written a utility call setfib
that acts a bit like nice..
setfib -3 ping target.example.com # will use fib 3 for ping.
It is an obvious extension to make it a property of a jail
but I have not done so. It can be achieved by combining the setfib and
jail commands.
2/ packets received on an interface for forwarding.
By default these packets would use table 0,
(or possibly a number settable in a sysctl(not yet)).
but prior to routing the firewall can inspect them (see below).
(possibly in the future you may be able to associate a FIB
with packets received on an interface.. An ifconfig arg, but not yet.)
3/ packets inspected by a packet classifier, which can arbitrarily
associate a fib with it on a packet by packet basis.
A fib assigned to a packet by a packet classifier
(such as ipfw) would over-ride a fib associated by
a more default source. (such as cases 1 or 2).
4/ a tcp listen socket associated with a fib will generate
accept sockets that are associated with that same fib.
5/ Packets generated in response to some other packet (e.g. reset
or icmp packets). These should use the FIB associated with the
packet being reponded to.
6/ Packets generated during encapsulation.
gif, tun and other tunnel interfaces will encapsulate using the FIB
that was in effect withthe proces that set up the tunnel.
thus setfib 1 ifconfig gif0 [tunnel instructions]
will set the fib for the tunnel to use to be fib 1.
Routing messages would be associated with their
process, and thus select one FIB or another.
messages from the kernel would be associated with the fib they
refer to and would only be received by a routing socket associated
with that fib. (not yet implemented)
In addition Netstat has been edited to be able to cope with the
fact that the array is now 2 dimensional. (It looks in system
memory using libkvm (!)). Old versions of netstat see only the first FIB.
In addition two sysctls are added to give:
a) the number of FIBs compiled in (active)
b) the default FIB of the calling process.
Early testing experience:
-------------------------
Basically our (IronPort's) appliance does this functionality already
using ipfw fwd but that method has some drawbacks.
For example,
It can't fully simulate a routing table because it can't influence the
socket's choice of local address when a connect() is done.
Testing during the generating of these changes has been
remarkably smooth so far. Multiple tables have co-existed
with no notable side effects, and packets have been routes
accordingly.
ipfw has grown 2 new keywords:
setfib N ip from anay to any
count ip from any to any fib N
In pf there seems to be a requirement to be able to give symbolic names to the
fibs but I do not have that capacity. I am not sure if it is required.
SCTP has interestingly enough built in support for this, called VRFs
in Cisco parlance. it will be interesting to see how that handles it
when it suddenly actually does something.
Where to next:
--------------------
After committing the ABI compatible version and MFCing it, I'd
like to proceed in a forward direction in -current. this will
result in some roto-tilling in the routing code.
Firstly: the current code's idea of having a separate tree per
protocol family, all of the same format, and pointed to by the
1 dimensional array is a bit silly. Especially when one considers that
there is code that makes assumptions about every protocol having the
same internal structures there. Some protocols don't WANT that
sort of structure. (for example the whole idea of a netmask is foreign
to appletalk). This needs to be made opaque to the external code.
My suggested first change is to add routing method pointers to the
'domain' structure, along with information pointing the data.
instead of having an array of pointers to uniform structures,
there would be an array pointing to the 'domain' structures
for each protocol address domain (protocol family),
and the methods this reached would be called. The methods would have
an argument that gives FIB number, but the protocol would be free
to ignore it.
When the ABI can be changed it raises the possibilty of the
addition of a fib entry into the "struct route". Currently,
the structure contains the sockaddr of the desination, and the resulting
fib entry. To make this work fully, one could add a fib number
so that given an address and a fib, one can find the third element, the
fib entry.
Interaction with the ARP layer/ LL layer would need to be
revisited as well. Qing Li has been working on this already.
This work was sponsored by Ironport Systems/Cisco
Reviewed by: several including rwatson, bz and mlair (parts each)
Obtained from: Ironport systems/Cisco
we're certain the allocation will entierly succeed. This fixes a leak in a
fairly unlikely case.
Reported by: vijay singh <vijjus at rocketmail dot com>
MFC after: 1 week
after each SYSINIT() macro invocation. This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.
MFC after: 1 month
Discussed with: imp, rink
for all network interfaces, not just ethernet-like ones.
Upgrade it to a louder WARNING and be explicit that the flag is obsolete.
Support for IFF_NEEDSGIANT will be removed in a few months (see arch@ for
details) and will not appear in 8.0.
Upgrade if_watchdog to a WARNING.
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:
mac_<object>_<method/action>
mac_<object>_check_<method/action>
The previous naming scheme was inconsistent and mostly
reversed from the new scheme. Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier. Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods. Also simplify, slightly,
some entry point names.
All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.
Sponsored by: SPARTA (original patches against Mac OS X)
Obtained from: TrustedBSD Project, Apple Computer
framework for non-MPSAFE network protocols:
- Remove debug_mpsafenet variable, sysctl, and tunable.
- Remove NET_NEEDS_GIANT() and associate SYSINITSs used by it to force
debug.mpsafenet=0 if non-MPSAFE protocols are compiled into the kernel.
- Remove logic to automatically flag interrupt handlers as non-MPSAFE if
debug.mpsafenet is set for an INTR_TYPE_NET handler.
- Remove logic to automatically flag netisr handlers as non-MPSAFE if
debug.mpsafenet is set.
- Remove references in a few subsystems, including NFS and Cronyx drivers,
which keyed off debug_mpsafenet to determine various aspects of their own
locking behavior.
- Convert NET_LOCK_GIANT(), NET_UNLOCK_GIANT(), and NET_ASSERT_GIANT into
no-op's, as their entire behavior was determined by the value in
debug_mpsafenet.
- Alias NET_CALLOUT_MPSAFE to CALLOUT_MPSAFE.
Many remaining references to NET_.*_GIANT() and NET_CALLOUT_MPSAFE are still
present in subsystems, and will be removed in followup commits.
Reviewed by: bz, jhb
Approved by: re (kensmith)
The name trunk is misused as the networking term trunk means carrying multiple
VLANs over a single connection. The IEEE standard for link aggregation (802.3
section 3) does not talk about 'trunk' at all while it is used throughout IEEE
802.1Q in describing vlans.
The lagg(4) driver provides link aggregation, failover and fault tolerance.
Discussed on: current@
tolerance. This driver allows aggregation of multiple network interfaces as
one virtual interface using a number of different protocols/algorithms.
failover - Sends traffic through the secondary port if the master becomes
inactive.
fec - Supports Cisco Fast EtherChannel.
lacp - Supports the IEEE 802.3ad Link Aggregation Control Protocol
(LACP) and the Marker Protocol.
loadbalance - Static loadbalancing using an outgoing hash.
roundrobin - Distributes outgoing traffic using a round-robin scheduler
through all active ports.
This code was obtained from OpenBSD and this also includes 802.3ad LACP support
from agr(4) in NetBSD.
structures. Detect when ifnet instances are detached from the network
stack and perform appropriate cleanup to prevent memory leaks.
This has been implemented in such a way as to be backwards ABI compatible.
Kernel consumers are changed to use if_delmulti_ifma(); in_delmulti()
is unable to detect interface removal by design, as it performs searches
on structures which are removed with the interface.
With this architectural change, the panics FreeBSD users have experienced
with carp and pfsync should be resolved.
Obtained from: p4 branch bms_netdev
Reviewed by: andre
Sponsored by: Garance A Drosehn
Idea from: NetBSD
MFC after: 1 month
a link-layer multicast group membership.
Such memberships are needed in order to support protocols such as
IS-IS without putting the interface into PROMISC or ALLMULTI modes.
sa_equal() is not OK for comparing sockaddr_dl as it has deeper structure
than a simple byte array, so add sa_dl_equal() and use that instead.
Reviewed by: rwatson
Verified with: /usr/sbin/mtest
Bug found by: Jouke Witteveen
MFC after: 2 weeks
if_watchdog/if_timer interface doesn't fit modern SMP network
stack design.
Device drivers that need watchdog to monitor their hardware should
implement it theirselves.
Eventually the if_watchdog/if_timer API will be removed. For now,
warn that driver uses it.
Reviewed by: scottl
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
and skip over the normal IP processing.
Add a supporting function ifa_ifwithbroadaddr() to verify and validate the
supplied subnet broadcast address.
PR: kern/99558
Tested by: Andrey V. Elsukov <bu7cher-at-yandex.ru>
Sponsored by: TCP/IP Optimization Fundraise 2005
MFC after: 3 days
parameter that can specify configuration parameters:
o rev cloner api's to add optional parameter block
o add SIOCCREATE2 that accepts parameter data
o rev vlan support to use new api (maintain old code)
Reviewed by: arch@
except in places dealing with ifaddr creation or destruction; and
in such special places incomplete ifaddrs should never be linked
to system-wide data structures. Therefore we can eliminate all the
superfluous checks for "ifa->ifa_addr != NULL" and get ready
to the system crashing honestly instead of masking possible bugs.
Suggested by: glebius, jhb, ru
list.
- First remove from global list, then start destroying.
PR: kern/97679
Submitted by: Alex Lyashkov <shadow itt.net.ru>
Reviewed by: rwatson, brooks
order to - for example - apply firewall rules to a whole group of
interfaces. This is required for importing pf from OpenBSD 3.9
Obtained from: OpenBSD (with changes)
Discussed on: -net (back in April)
notification so all interfaces including pseudo are reported. When netif
creates the clones at startup devctl_disable has not been turned off yet so the
interfaces will not be initialised twice, enforce this by adding an explicit
order between rc.d/netif and rc.d/devd.
This change allows actions to taken in userland when an interface is cloned
and the pseudo interface will be automatically configured if a ifconfig_<int>=""
line exists in rc.conf.
Reviewed by: brooks
No objections on: net
work by yar, thompsa and myself. The checksum offloading part also involves
work done by Mihail Balikov.
The most important changes:
o Instead of global linked list of all vlan softc use a per-trunk
hash. The size of hash is dynamically adjusted, depending on
number of entries. This changes struct ifnet, replacing counter
of vlans with a pointer to trunk structure. This change is an
improvement for setups with big number of VLANs, several interfaces
and several CPUs. It is a small regression for a setup with a single
VLAN interface.
An alternative to dynamic hash is a per-trunk static array with
4096 entries, which is a compile time option - VLAN_ARRAY. In my
experiments the array is not an improvement, probably because such
a big trunk structure doesn't fit into CPU cache.
o Introduce an UMA zone for VLAN tags. Since drivers depend on it,
the zone is declared in kern_mbuf.c, not in optional vlan(4) driver.
This change is a big improvement for any setup utilizing vlan(4).
o Use rwlock(9) instead of mutex(9) for locking. We are the first
ones to do this! :)
o Some drivers can do hardware VLAN tagging + hardware checksum
offloading. Add an infrastructure for this. Whenever vlan(4) is
attached to a parent or parent configuration is changed, the flags
on vlan(4) interface are updated.
In collaboration with: yar, thompsa
In collaboration with: Mihail Balikov <mihail.balikov interbgc.com>
rather than in ifindex_table[]; all (except one) accesses are
through ifp anyway. IF_LLADDR() works faster, and all (except
one) ifaddr_byindex() users were converted to use ifp->if_addr.
- Stop storing a (pointer to) Ethernet address in "struct arpcom",
and drop the IFP2ENADDR() macro; all users have been converted
to use IF_LLADDR() instead.
copy of Ethernet address.
- Change iso88025_ifattach() and fddi_ifattach() to accept MAC
address as an argument, similar to ether_ifattach(), to make
this work.
as it is done for usual promiscuous mode already. This info is important
because promiscuous mode in the hands of a malicious party can jeopardize
the whole network.
panics, which occur when stale ifnet pointers are left in struct
moptions hung off of inpcbs:
- Add in_ifdetach(), which matches in6_ifdetach(), and allows the
protocol to perform early tear-down on the interface early in
if_detach().
- Annotate that if_detach() needs careful consideration.
- Remove calls to in_pcbpurgeif0() in the handling of SIOCDIFADDR --
this is not the place to detect interface removal! This also
removes what is basically a nasty (and now unnecessary) hack.
- Invoke in_pcbpurgeif0() from in_ifdetach(), in both raw and UDP
IPv4 sockets.
It is now possible to run the msocket_ifnet_remove regression test
using HEAD without panicking.
MFC after: 3 days
struct ifnet most of if_findindex() become a complex no-op. Remove it
and replace it with a corrected version of the four line for loop it
devolved to plus some error handling. This should probably be replaced
with subr_unit at some point.
Switch from checking ifaddr_byindex to ifnet_byindex when looking for
empty indexes. Since we're doing this from if_alloc/if_free, we can
only be sure that ifnet_byindex will be correct. This fixes panics when
loading the ef(4) module. The panics were caused by the fact that
if_alloc was called four time before if_attach was called and thus
ifaddr_byindex was not set and the same unit was allocated again. This
in turn caused the first if_attach to fail because the ifp was not the
one in ifnet_byindex(ifp->if_index).
Reported by: "Wojciech A. Koszek" <dunstan at freebsd dot czest dot pl>
PR: kern/84987
MFC After: 1 day
- Add a note that additions should be made to if_free_type and not
if_free to help avoid this in the future.
This apparently fixes a use after free in if_bridge and may fix bugs
in other direct if_free_type consumers.
Reported by: thompsa
and move both flags from ifnet.if_flags to ifnet.if_drv_flags, making
and documenting the locking of these flags the responsibility of the
device driver, not the network stack. The flags for these two fields
will be mutually exclusive so that they can be exposed to user space as
though they were stored in the same variable.
Provide #defines to provide the old names #ifndef _KERNEL, so that user
applications (such as ifconfig) can use the old flag names. Using the
old names in a device driver will result in a compile error in order to
help device driver writers adopt the new model.
When exposing the interface flags to user space, via interface ioctls
or routing sockets, or the two fields together. Since the driver flags
cannot currently be set for user space, no new logic is currently
required to handle this case.
Add some assertions that general purpose network stack routines, such
as if_setflags(), are not improperly used on driver-owned flags.
With this change, a large number of very minor network stack races are
closed, subject to correct device driver locking. Most were likely
never triggered.
Driver sweep to follow; many thanks to pjd and bz for the line-by-line
review they gave this patch.
Reviewed by: pjd, bz
MFC after: 7 days
if_attach(). This allows ethernet drivers to use it in their routines
to program their MAC filters before ether_ifattach() is called (de(4) is
one such driver). Also, the if_addr mutex is destroyed in if_free()
rather than if_detach(), so there was another potential bug in that a
driver that failed during attach and called if_free() without having
called ether_ifattach() would have tried to destroy an uninitialized mutex.
Reported by: Holm Tiffe holm at freibergnet dot de
Discussed with: rwatson
using ifp->if_addr_mtx:
- Initialize if_addr_mtx when ifnet is initialized.
- Destroy if_addr_mtx when ifnet is torn down.
- Rename ifmaof_ifpforaddr() to if_findmulti(); assert if_addr_mtx.
Staticize.
- Extract ifmultiaddr allocation and initialization into if_allocmulti();
accept a 'mflags' argument to indicate whether or not sleeping is
permitted. This centralizes error handling and address duplication.
- Extract ifmultiaddr tear-down and deallocation in if_freemulti().
- Re-structure if_addmulti() to hold if_addr_mtx around manipulation of
the ifnet multicast address list and reference count manipulation.
Make use of non-sleeping allocations. Annotate the fact that we only
generate routing socket events for explicit address addition, not
implicit link layer address addition.
- Re-structure if_delmulti() to hold if_addr_mtx around manipulation of
the ifnet multicast address list and reference count manipulation.
Annotate the lack of a routing socket event for implicit link layer
address removal.
- De-spl all and sundry.
Problem reported by: Ed Maste <emaste at phaedrus dot sandvine dot ca>
MFC after: 1 week
Compare pointers with NULL rather than treating them as booleans.
Compare pointers with NULL rather than 0 to make it more clear
they are pointers.
Assign pointers value of NULL rather than 0 to make it more clear
they are pointers.
MFC after: 3 days
Some of the (IPv6) cleanup functions send packets to inform peers of the
departure. These packets confused users of ifnet_departure_event (pf at the
moment).
PR: kern/80627
Tested by: Divacky Roman
MFC after: 1 week
- Introduce a helper function if_setflag() containing the code common
to ifpromisc() and if_allmulti() instead of duplicating the code poorly,
with different bugs.
- Call ifp->if_ioctl() in a consistent way: always use more compatible C
syntax and check whether ifp->if_ioctl is not NULL prior to the call.
MFC after: 1 month
- Introducing the possibility of using locks different than mutexes
for the knlist locking. In order to do this, we add three arguments to
knlist_init() to specify the functions to use to lock, unlock and
check if the lock is owned. If these arguments are NULL, we assume
mtx_lock, mtx_unlock and mtx_owned, respectively.
- Using the vnode lock for the knlist locking, when doing kqueue operations
on a vnode. This way, we don't have to lock the vnode while holding a
mutex, in filt_vfsread.
Reviewed by: jmg
Approved by: re (scottl), scottl (mentor override)
Pointyhat to: ssouhlal
Will be happy: everyone
fails.
Move detaching the ifnet from the ifindex_table into if_free so we can
both keep the sanity checks and actually delete the ifnets. [0]
Reported by: gallatin [0]
Approved by: re (blanket)
