Commit graph

83 commits

Author SHA1 Message Date
Michael Tuexen 4e88d37a2a Do the renaming of sb_cc to sb_ccc in a way with less code changes by
using a macro.
This is an alternate approach to
https://svnweb.freebsd.org/changeset/base/275326
which is easier to handle upstream.

Discussed with: rrs, glebius
2014-12-02 20:29:29 +00:00
Gleb Smirnoff 0f9d0a73a4 Merge from projects/sendfile:
o Introduce a notion of "not ready" mbufs in socket buffers.  These
mbufs are now being populated by some I/O in background and are
referenced outside.  This forces following implications:
- An mbuf which is "not ready" can't be taken out of the buffer.
- An mbuf that is behind a "not ready" in the queue neither.
- If sockbet buffer is flushed, then "not ready" mbufs shouln't be
  freed.

o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc.
  The sb_ccc stands for ""claimed character count", or "committed
  character count".  And the sb_acc is "available character count".
  Consumers of socket buffer API shouldn't already access them directly,
  but use sbused() and sbavail() respectively.
o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones
  with M_BLOCKED.
o New field sb_fnrdy points to the first not ready mbuf, to avoid linear
  search.
o New function sbready() is provided to activate certain amount of mbufs
  in a socket buffer.

A special note on SCTP:
  SCTP has its own sockbufs.  Unfortunately, FreeBSD stack doesn't yet
allow protocol specific sockbufs.  Thus, SCTP does some hacks to make
itself compatible with FreeBSD: it manages sockbufs on its own, but keeps
sb_cc updated to inform the stack of amount of data in them.  The new
notion of "not ready" data isn't supported by SCTP.  Instead, only a
mechanical substitute is done: s/sb_cc/sb_ccc/.
  A proper solution would be to take away struct sockbuf from struct
socket and allow protocols to implement their own socket buffers, like
SCTP already does.  This was discussed with rrs@.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-11-30 12:52:33 +00:00
Michael Tuexen 43f9f175c5 The MTU is handled as a 32-bit entity within the SCTP stack.
This was reported by Peter Kasting from Google.

MFC after: 3 days
2014-09-16 09:22:43 +00:00
Michael Tuexen f47f328dc5 Fix the handling of sysctl variables when used with VIMAGE.
While there do some cleanup of the code.

MFC after: 1 week
2014-09-06 19:12:14 +00:00
Michael Tuexen 0c8682e8ad Whitespace changes.
MFC after: 1 week
2014-07-11 21:15:40 +00:00
Gleb Smirnoff fcc34a238c Fix style bug: rename the refcount field of m_ext to ext_cnt, to match
other members.

Sponsored by:	Nginx, Inc.
2014-07-11 14:34:29 +00:00
Gleb Smirnoff e3a7aa6f56 - Remove rt_metrics_lite and simply put its members into rtentry.
- Use counter(9) for rt_pksent (former rt_rmx.rmx_pksent). This
  removes another cache trashing ++ from packet forwarding path.
- Create zini/fini methods for the rtentry UMA zone. Via initialize
  mutex and counter in them.
- Fix reporting of rmx_pksent to routing socket.
- Fix netstat(1) to report "Use" both in kvm(3) and sysctl(3) mode.

The change is mostly targeted for stable/10 merge. For head,
rt_pksent is expected to just disappear.

Discussed with:		melifaro
Sponsored by:		Netflix
Sponsored by:		Nginx, Inc.
2014-03-05 01:17:47 +00:00
Michael Tuexen e6b2b4b65b All changes affect only SCTP-AUTH:
* Remove non working code related to SHA224.
* Remove support for non-standardised HMAC-IDs using SHA384 and SHA512.
* Prefer SHA256 over SHA1.
* Minor cleanup.

MFC after: 2 weeks
2013-09-02 22:48:41 +00:00
Andre Oppermann 5fc98a7895 Reorder the mbuf defines to make more sense and group related flags
together.

Add M_FLAG_PRINTF for use with printf(9) %b indentifier.

Use the generic mbuf flags print names in the net80211 code and adjust
the protocol specific bits for their new positions.

Change SCTP M_PROTO mapping from 5 to 1 to fit within the 16bit field
they use internally to store some additional information.

Discussed with:	trociny, glebius
2013-08-19 14:25:11 +00:00
Andre Oppermann 86bd049144 Add m_clrprotoflags() to clear protocol specific mbuf flags at up and
downwards layer crossings.

Consistently use it within IP, IPv6 and ethernet protocols.

Discussed with:	trociny, glebius
2013-08-19 13:27:32 +00:00
Andre Oppermann 678d7b9461 Move the SCTP specific definition of M_NOTIFICATION onto a protocol
specific mbuf flag from sys/mbuf.h to netinet/sctp_os_bsd.h.  It is
only relevant within SCTP.

Discussed with:	tuexen
2013-08-19 12:30:18 +00:00
Michael Tuexen 3f61f926ea Withdraw http://svnweb.freebsd.org/changeset/base/250809
since the real fix is in http://svnweb.freebsd.org/changeset/base/250952.
2013-05-24 09:21:18 +00:00
Michael Tuexen e3581df21e Initialize the fibnum for outgoing packets to 0. This avoids
crashing due to the usage of uninitialized fibnum.
This bugs became visiable after
http://svnweb.freebsd.org/changeset/base/250700

MFC after: 2 weeks
2013-05-19 16:06:43 +00:00
Michael Tuexen b1754ad17b Pass the src and dst address of a received packet explicitly around.
MFC after: 3 days
2012-06-28 16:01:08 +00:00
Michael Tuexen f938425253 Do packet logging in a consistent way.
MFC after: 3 days
2012-06-24 21:25:54 +00:00
Michael Tuexen 807aad636f Use consistent text at the begining of the files.
MFC after: 3 days
2012-05-23 11:26:28 +00:00
Michael Tuexen cd3fd53188 Use SCTP_PRINTF() instead of printf() in all SCTP sources.
MFC after: 3 days
2012-05-04 09:27:00 +00:00
Bjoern A. Zeeb 9836132cd1 Document the fact that multi-FIB support for SCTP had been backed out
in r179783 as (ab)using the concept of VRFs for this had not worked.
At this point SCTP in FreeBSD does not support multi-FIB, neither for
IPv4 nor for IPv6.

Discussed with:	rrs
Sponsored by:	Cisco Systems, Inc.
2012-02-03 15:39:13 +00:00
Michael Tuexen d085528d04 Remove some leftover debug code.
MFC after: 1 week
2011-04-30 11:22:30 +00:00
Michael Tuexen e6194c2ed4 Improve compilation of SCTP code without INET support.
Some bugs where fixed while doing this:
* ASCONF-ACK messages might use wrong port number when using
  IPv6.
* Checking for additional addresses takes the correct address
  into account and also does not do more comparisons than
  necessary.

This patch is based on one received from bz@ who was
sponsored by The FreeBSD Foundation and iXsystems.

MFC after: 1 week
2011-04-30 11:18:16 +00:00
Randall Stewart 5d40cf5d23 1) Typo correction in comments and one spacing change.
2) Mass update to all copyrights.
MFC after:	3 Months
2011-02-05 12:12:51 +00:00
Randall Stewart bfc46083b9 Adds an experimental option to create a pool of
threads. These serve as input threads and are queued
packets based on the V-tag number. This is similar to
what a modern card can do with queue's for TCP... but
alas modern cards know nothing about SCTP.

MFC after:	3 months (maybe)
2011-02-03 10:05:30 +00:00
Rebecca Cran b1ce21c6ef Fix typos.
PR:	bin/148894
Submitted by:	olgeni
2010-11-09 10:59:09 +00:00
Michael Tuexen 9c7635e18b Fix the the SCTP_WITH_NO_CSUM option when used in combination with
interface supporting CRC offload. While at it, make use of the
feature that the loopback interface provides CRC offloading.

MFC after: 4 weeks
2010-08-29 18:50:30 +00:00
Michael Tuexen 5661a9ed70 Get rid of support of an old version of the SCTP-AUTH draft.
Get rid of unused MD5 code.

MFC after: 1 week
2010-01-16 20:04:17 +00:00
Michael Tuexen 83fc1165c5 Use always LIST_EMPTY instead of sometime SCTP_LIST_EMPTY,
which is defined as LIST_EMPTY.

Approved by: rrs (mentor)
MFC after: 1 month
2009-11-17 20:56:14 +00:00
Michael Tuexen cf458c646d Allow the UMA to free data. This resolves the UMA related bug reported
by Julian.

Approved by: rrs (mentor)
MFC after: 1 month
2009-11-17 13:08:15 +00:00
Michael Tuexen 45623593fb Correct include order as indicated by bz.
Approved by: re (mentor)
MFC after: 3 days
2009-10-10 13:59:18 +00:00
Michael Tuexen 3b1de911e0 Do not include vnet.h twice.
Approved by: rrs (mentor)
MFC after: 3 days
2009-10-09 19:30:23 +00:00
Michael Tuexen 8518270e20 Get SCTP working in combination with VIMAGE.
Contains code from bz.
Approved by: rrs (mentor)
MFC after: 1 month.
2009-09-19 14:02:16 +00:00
Randall Stewart 482444b4a5 Support for VNET in SCTP (hopefully) 2009-09-17 15:11:12 +00:00
Marko Zec f92ae4d706 SCTP is not yet compatible with options VIMAGE kernels although it compiles
with VIMAGE defined, so explicitly disallow building such kernels.

Reviewed by:	rrs
Approved by:	re (rwatson), julian (mentor)
2009-08-14 22:43:25 +00:00
Robert Watson 530c006014 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
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)
2009-08-01 19:26:27 +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
Bjoern A. Zeeb 8d8bc0182e After r193232 rt_tables in vnet.h are no longer indirectly dependent on
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.
2009-06-08 19:57:35 +00:00
Marko Zec 743da3bcdb Unbreak options VIMAGE kernel builds.
Approved by:	julian (mentor)
2009-05-06 08:49:39 +00:00
Randall Stewart dfb11ef895 - PR-SCTP bug, where the CUM-ACK was not being updated
into the advance_peer_ack point so we would incorrectly
  send a wrong value in the FWD-TSN
- PR-SCTP bug, where an PR packet is used for a window
  probe which could incorrectly get the packet moved
  back into the send_queue, which will cause major issues and
  should not happen.
- Fix a trace to use the proper macro.
2009-03-04 20:54:42 +00:00
Bjoern A. Zeeb 33553d6e99 For all files including net/vnet.h directly include opt_route.h and
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.
2009-02-27 14:12:05 +00:00
Randall Stewart a99b67833a - Cleanup checksum code.
- Prepare for CRC offloading, add MIB counters (RS/MT).
- Bugfix: Disable CRC computation for IPv6 addresses with local scope (MT).
- Bugfix: Handle close() with SO_LINGER correctly when notifications
          are generated during the close() call(MT).
- Bugfix: Generate DRY event when sender is dry during subscription.
          Only for 1-to-1 style sockets (RS/MT)
- Bugfix: Put vtags for the correct amount of time into time-wait (MT).
- Bugfix: Clear vtag entries correctly on expiration (MT).
- Bugfix: shutdown() indicates ENOTCONN when called for unconnected
          1-to-1 style sockets (MT).
- Bugfix: In sctp Auth code (PL).
- Add support for devices that support SCTP csum offload (igb).
- Add missing sctp_associd to mib sysctl xsctp_tcb structure (RS)
Obtained from:	With help from Peter Lei and Michael Tuexen
2009-02-03 11:04:03 +00:00
Marko Zec 385195c062 Conditionally compile out V_ globals while instantiating the appropriate
container structures, depending on VIMAGE_GLOBALS compile time option.

Make VIMAGE_GLOBALS a new compile-time option, which by default will not
be defined, resulting in instatiations of global variables selected for
V_irtualization (enclosed in #ifdef VIMAGE_GLOBALS blocks) to be
effectively compiled out.  Instantiate new global container structures
to hold V_irtualized variables: vnet_net_0, vnet_inet_0, vnet_inet6_0,
vnet_ipsec_0, vnet_netgraph_0, and vnet_gif_0.

Update the VSYM() macro so that depending on VIMAGE_GLOBALS the V_
macros resolve either to the original globals, or to fields inside
container structures, i.e. effectively

#ifdef VIMAGE_GLOBALS
#define V_rt_tables rt_tables
#else
#define V_rt_tables vnet_net_0._rt_tables
#endif

Update SYSCTL_V_*() macros to operate either on globals or on fields
inside container structs.

Extend the internal kldsym() lookups with the ability to resolve
selected fields inside the virtualization container structs.  This
applies only to the fields which are explicitly registered for kldsym()
visibility via VNET_MOD_DECLARE() and vnet_mod_register(), currently
this is done only in sys/net/if.c.

Fix a few broken instances of MODULE_GLOBAL() macro use in SCTP code,
and modify the MODULE_GLOBAL() macro to resolve to V_ macros, which in
turn result in proper code being generated depending on VIMAGE_GLOBALS.

De-virtualize local static variables in sys/contrib/pf/net/pf_subr.c
which were prematurely V_irtualized by automated V_ prepending scripts
during earlier merging steps.  PF virtualization will be done
separately, most probably after next PF import.

Convert a few variable initializations at instantiation to
initialization in init functions, most notably in ipfw.  Also convert
TUNABLE_INT() initializers for V_ variables to TUNABLE_FETCH_INT() in
initializer functions.

Discussed at:	devsummit Strassburg
Reviewed by:	bz, julian
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-12-10 23:12:39 +00:00
Randall Stewart 830d754d52 Code from the hack-session known as the IETF (and a
bit of debugging afterwards):
- Fix protection code for notification generation.
- Decouple associd from vtag
- Allow vtags to have less strigent requirements in non-uniqueness.
   o don't pre-hash them when you issue one in a cookie.
   o Allow duplicates and use addresses and ports to
     discriminate amongst the duplicates during lookup.
- Add support for the NAT draft draft-ietf-behave-sctpnat-00, this
  is still experimental and needs more extensive testing with the
  Jason Butt ipfw changes.
- Support for the SENDER_DRY event to get DTLS in OpenSSL working
  with a set of patches from Michael Tuexen (hopefully heading to OpenSSL soon).
- Update the support of SCTP-AUTH by Peter Lei.
- Use macros for refcounting.
- Fix MTU for UDP encapsulation.
- Fix reporting back of unsent data.
- Update assoc send counter handling to be consistent with endpoint sent counter.
- Fix a bug in PR-SCTP.
- Fix so we only send another FWD-TSN when a SACK arrives IF and only
  if the adv-peer-ack point progressed. However we still make sure
  a timer is running if we do have an adv_peer_ack point.
- Fix PR-SCTP bug where chunks were retransmitted if they are sent
  unreliable but not abandoned yet.

With the help of:	Michael Teuxen and Peter Lei :-)
MFC after:	 4 weeks
2008-12-06 13:19:54 +00:00
Bjoern A. Zeeb 4b79449e2f Rather than using hidden includes (with cicular dependencies),
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
2008-12-02 21:37:28 +00:00
Randall Stewart a4c651183e Get rid of ifdef for vimage on version 8 comparison. Now the
scrubbing program properly takes care of this.
2008-10-27 13:54:54 +00:00
Dag-Erling Smørgrav 1ede983cc9 Retire the MALLOC and FREE macros. They are an abomination unto style(9).
MFC after:	3 months
2008-10-23 15:53:51 +00:00
Bjoern A. Zeeb 603724d3ab Commit step 1 of the vimage project, (network stack)
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
2008-08-17 23:27:27 +00:00
Randall Stewart fc14de76f4 1) Adds the rest of the VIMAGE change macros
2) Adds some __UserSpace__ on some of the common defines that
   the user space code needs
3) Fixes a bug when we send up data to a user that failed. We
   need to a) trim off the data chunk headers, if present, and
   b) make sure the frag bit is communicated properly for the
   msgs coming off the stream queues... i.e. we see if some
   of the msg has been taken.

Obtained from:	jeli contributed the VIMAGE changes on this pass Thanks Julain!
2008-07-09 16:45:30 +00:00
Randall Stewart 9b02321796 - Fixes foobar on my part. Some missing virtualization macros from
specific logging cases.
2008-06-14 13:24:49 +00:00
Randall Stewart b3f1ea41fd - Macro-izes the packed declaration in all headers.
- Vimage prep - these are major restructures to move
  all global variables to be accessed via a macro or two.
  The variables all go into a single structure.
- Asconf address addition tweaks (add_or_del Interfaces)
- Fix rwnd calcualtion to be more conservative.
- Support SACK_IMMEDIATE flag to skip delayed sack
  by demand of peer.
- Comment updates in the sack mapping calculations
- Invarients panic added.
- Pre-support for UDP tunneling (we can do this on
  MAC but will need added support from UDP to
  get a "pipe" of UDP packets in.
- clear trace buffer sysctl added when local tracing on.

Note the majority of this huge patch is all the vimage prep stuff :-)
2008-06-14 07:58:05 +00:00
Randall Stewart c54a18d26b - Adds support for the multi-asconf (From Kozuka-san)
- Adds some prepwork (Not all yet) for vimage in particular
  support the delete the sctppcbinfo.xx structs. There is
  still a leak in here if it were to be called plus we stil
  need the regrouping (From Me and Michael Tuexen)
- Adds support for UDP tunneling. For BSD there is no
  socket yet setup so its disabled, but major argument
  changes are in here to emcompass the passing of the port
  number (zero when you don't have a udp tunnel, the default
  for BSD). Will add some hooks in UDP here shortly (discussed
  with Robert) that will allow easy tunneling. (Mainly from
  Peter Lei and Michael Tuexen with some BSD work from me :-D)
- Some ease for windows, evidently leave is reserved by their
  compile move label leave: -> out:

MFC after:	1 week
2008-05-20 13:47:46 +00:00
Julian Elischer 8b07e49a00 Add code to allow the system to handle multiple routing tables.
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
2008-05-09 23:03:00 +00:00