several critical bugs, including race conditions and lock order issues:
Replace the single rwlock, ifnet_lock, with two locks, an rwlock and an
sxlock. Either can be held to stablize the lists and indexes, but both
are required to write. This allows the list to be held stable in both
network interrupt contexts and sleepable user threads across sleeping
memory allocations or device driver interactions. As before, writes to
the interface list must occur from sleepable contexts.
Reviewed by: bz, julian
MFC after: 3 days
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks. Minor cleanups are done in the process,
and comments updated to reflect these changes.
Reviewed by: bz
Approved by: re (vimage blanket)
(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)
the ROUTETABLES kernel option thus there is no need to include opt_route.h
anymore in all consumers of vnet.h and no longer depend on it for module
builds.
Remove the hidden include in flowtable.h as well and leave the two
explicit #includes in ip_input.c and ip_output.c.
net/route.h.
Remove the hidden include of opt_route.h and net/route.h from net/vnet.h.
We need to make sure that both opt_route.h and net/route.h are included
before net/vnet.h because of the way MRT figures out the number of FIBs
from the kernel option. If we do not, we end up with the default number
of 1 when including net/vnet.h and array sizes are wrong.
This does not change the list of files which depend on opt_route.h
but we can identify them now more easily.
directly include only the header files needed. This reduces the
unneeded spamming of various headers into lots of files.
For now, this leaves us with very few modules including vnet.h
and thus needing to depend on opt_route.h.
Reviewed by: brooks, gnn, des, zec, imp
Sponsored by: The FreeBSD Foundation
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit
Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.
Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().
Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).
All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).
(*) netipsec/keysock.c did not validate depending on compile time options.
Implemented by: julian, bz, brooks, zec
Reviewed by: julian, bz, brooks, kris, rwatson, ...
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation
virtualization work done by Marko Zec (zec@).
This is the first in a series of commits over the course
of the next few weeks.
Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.
We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.
Obtained from: //depot/projects/vimage-commit2/...
Reviewed by: brooks, des, ed, mav, julian,
jamie, kris, rwatson, zec, ...
(various people I forgot, different versions)
md5 (with a bit of help)
Sponsored by: NLnet Foundation, The FreeBSD Foundation
X-MFC after: never
V_Commit_Message_Reviewed_By: more people than the patch
queue so the output network card must support the same tagging mechanism as
how the frame was input (prepended Ethernet header tag or stripped HW mflag).
Now the vlan Ethernet header is _always_ stripped in ether_input and the mbuf
flagged, only only network cards with VLAN_HWTAGGING enabled would properly
re-tag any outgoing vlan frames.
If the outgoing interface does not support hardware tagging then readd the vlan
header to the front of the frame. Move the common vlan encapsulation in to
ether_vlanencap().
Reported by: Erik Osterholm, Jon Otterholm
MFC after: 1 week
This can help to spot bugs (which it did for me,)
and let people know which mode the vlan module is
actually using if they suspect it isn't picking its
options from the main kernel config file.
- ifv_list member of struct ifvlan is unneeded in array mode,
it's used only in hash mode to resolve hash collisions.
- We don't need the list of trunks at all. (The initial reason for
having it was to be able to destroy all trunks in the MOD_UNLOAD
handler, but a trunk is not to be destroyed forcibly -- it will
go away when all vlan interfaces on it have been deleted.
Note that if_clone_detach() called first of all under MOD_UNLOAD
will delete all vlan interfaces and thus make all trunks go away
quietly.)
- It's enough to use a single [S]LIST_FIRST() in a typical list
destruction loop.
- Micro-optimize the addition of an 802.1q header to match the removal code.
- Consistently check for interfaces being up and running.
- Consistently use NULL instead of 0 with pointers.
m_pkthdr.ether_vlan. The presence of the M_VLANTAG flag on the mbuf
signifies the presence and validity of its content.
Drivers that support hardware VLAN tag stripping fill in the received
VLAN tag (containing both vlan and priority information) into the
ether_vtag mbuf packet header field:
m->m_pkthdr.ether_vtag = vlan_id; /* ntohs()? */
m->m_flags |= M_VLANTAG;
to mark the packet m with the specified VLAN tag.
On output the driver should check the mbuf for the M_VLANTAG flag to
see if a VLAN tag is present and valid:
if (m->m_flags & M_VLANTAG) {
... = m->m_pkthdr.ether_vtag; /* htons()? */
... pass tag to hardware ...
}
VLAN tags are stored in host byte order. Byte swapping may be necessary.
(Note: This driver conversion was mechanic and did not add or remove any
byte swapping in the drivers.)
Remove zone_mtag_vlan UMA zone and MTAG_VLAN definition. No more tag
memory allocation have to be done.
Reviewed by: thompsa, yar
Sponsored by: TCP/IP Optimization Fundraise 2005
by restoring the ifv_proto field in the vlan softc and putting it to use
this time. It's a good companion for ifv_encaplen, which has already been
used throughout this driver.
before tagging them. This can help to work around brain-damage in some
switches that fail to pad a frame after untagging it if its length drops
below the minimum. This option is blessed by IEEE Std 802.1Q (2003 Ed.),
paragraph C.4.4.3.b. It's controlled by sysctl net.link.vlan.soft_pad.
Idea by: az
MFC after: 1 week
interface, do not just assign -1 to tag because it breaks the logic of
the code to follow. The better way is to handle this case as an unsupported
protocol and return unless INVARIANTS is in effect and we can panic.
Panic is good there because the scenario can happen only because of a
coding error elsewhere.
We also should show the interface name in the panic message for easier
debugging of the problem, should it ever emerge.
Submitted by: qingli (initially)
as it tried to solve:
- it smuggled hidden 802.1q details into otherwise protocol-neutral code;
- it put an important code consistency check under DEBUG, which was never
defined by anyone but a developer hacking this file for the moment;
- lastly, the former bcopy() call had been correct as long as the "dead"
code was there.
(A new version of the fix for tag of -1 to come in the next commit.)
Agreed by: qingli
vlan tag processing, the code will use bcopy() to remove the vlan
tag field but the code copies 2 bytes too many, which essentially
overwrites the protocol type field.
Also, a tag value of -1 is generated for unrecognized interface type,
which would cause an invalid memory access in the vlans[] array.
In addition, removed a line of dead code and its associated comments.
Reviewed by: sam
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@
Previously, another thread could get a pointer to the
interface by scanning the system-wide list and sleep
on the global vlan mutex held by vlan_unconfig().
The interface was gone by the time the other thread
woke up.
In order to be able to call vlan_unconfig() on a detached
interface, remove the purely cosmetic bzero'ing of IF_LLADDR
from the function because a detached interface has no addresses.
Noticed by: a stress-testing script by maxim
Reviewed by: glebius
departing trunk so that we don't get into trouble later
by dereferencing a stale pointer to dead trunk's things.
Prodded by: oleg
Sponsored by: RiNet (Cronyx Plus LLC)
MFC after: 1 week
zero in this case.) A kernel driver has IFF_DRV_RUNNING
at its full disposal while IFF_UP may be toggled only by
humans or their daemonic deputies from the userland.
MFC after: 3 days
beginning and simply refuse to attach to a parent without either
flag.
Our network stack cannot handle well IFF_BROADCAST or IFF_MULTICAST
on an interface changing on the fly. E.g., IP will or won't assign
a broadcast address to an interface and join the all-hosts multicast
group on it depending on its IFF_BROADCAST and IFF_MULTICAST settings.
Should the flags alter later, IP will miss the change and keep using
bogus settings. This can lead to evil things like supplying an
invalid broadcast address or trying to leave a multicast group that
hasn't been joined. So just avoid touching the flags since an
interface was created. This has no practical purpose.
Discussed with: -net, glebius, oleg
MFC after: 1 week
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.
