Commit Graph

188 Commits

Author SHA1 Message Date
Pedro F. Giffuni
99d628d577 netinet: for pointers replace 0 with NULL.
These are mostly cosmetical, no functional change.

Found with devel/coccinelle.

Reviewed by:	ae. tuexen
2016-04-15 15:46:41 +00:00
Alexander V. Chernikov
10e0e23528 Remove now-unused wrappers for various routing functions. 2016-01-14 08:54:44 +00:00
Alexander V. Chernikov
ea8d14925c Remove sys/eventhandler.h from net/route.h
Reviewed by:	ae
2016-01-09 09:34:39 +00:00
Jung-uk Kim
fd90e2ed54 CALLOUT_MPSAFE has lost its meaning since r141428, i.e., for more than ten
years for head.  However, it is continuously misused as the mpsafe argument
for callout_init(9).  Deprecate the flag and clean up callout_init() calls
to make them more consistent.

Differential Revision:	https://reviews.freebsd.org/D2613
Reviewed by:	jhb
MFC after:	2 weeks
2015-05-22 17:05:21 +00:00
Gleb Smirnoff
6d947416cc o Use new function ip_fillid() in all places throughout the kernel,
where we want to create a new IP datagram.
o Add support for RFC6864, which allows to set IP ID for atomic IP
  datagrams to any value, to improve performance. The behaviour is
  controlled by net.inet.ip.rfc6864 sysctl knob, which is enabled by
  default.
o In case if we generate IP ID, use counter(9) to improve performance.
o Gather all code related to IP ID into ip_id.c.

Differential Revision:		https://reviews.freebsd.org/D2177
Reviewed by:			adrian, cy, rpaulo
Tested by:			Emeric POUPON <emeric.poupon stormshield.eu>
Sponsored by:			Netflix
Sponsored by:			Nginx, Inc.
Relnotes:			yes
2015-04-01 22:26:39 +00:00
Gleb Smirnoff
6df8a71067 Remove SYSCTL_VNET_* macros, and simply put CTLFLAG_VNET where needed.
Sponsored by:	Nginx, Inc.
2014-11-07 09:39:05 +00:00
Robert Watson
f0cace5d94 When deciding whether to call m_pullup() even though there is adequate
data in an mbuf, use M_WRITABLE() instead of a direct test of M_EXT;
the latter both unnecessarily exposes mbuf-allocator internals in the
protocol stack and is also insufficient to catch all cases of
non-writability.

(NB: m_pullup() does not actually guarantee that a writable mbuf is
returned, so further refinement of all of these code paths continues to
be required.)

Reviewed by:	bz
MFC after:	3 days
Sponsored by:	EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D900
2014-10-12 15:49:52 +00:00
Kevin Lo
73d76e77b6 Change pr_output's prototype to avoid the need for explicit casts.
This is a follow up to r269699.

Phabric:	D564
Reviewed by:	jhb
2014-08-15 02:43:02 +00:00
Kevin Lo
8f5a8818f5 Merge 'struct ip6protosw' and 'struct protosw' into one. Now we have
only one protocol switch structure that is shared between ipv4 and ipv6.

Phabric:	D476
Reviewed by:	jhb
2014-08-08 01:57:15 +00:00
Gleb Smirnoff
547246a373 Fix fallout from r241923. Calculate length of payload in
pim_input() properly.

While here, remove extra variable and incorrect condition
before m_pullup().

Reported by:	Olivier Cochard-Labbé <olivier cochard.me>
Sponsored by:	Nginx, Inc.
2014-01-22 10:57:42 +00:00
Gleb Smirnoff
76039bc84f The r48589 promised to remove implicit inclusion of if_var.h soon. Prepare
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-26 17:58:36 +00:00
John Baldwin
86d93a15ff Use LIST_FOREACH_SAFE() instead of doing it by hand. 2013-09-05 14:26:37 +00:00
John Baldwin
fa302f207f Use an unsigned long when indexing into mfchashtbl[] and mf6ctable[]. This
matches the types used when computing hash indices and the type of the
maximum size of mfchashtbl[].

PR:		kern/181821
Submitted by:	Sven-Thorsten Dietrich <sven@vyatta.com> (IPv4)
MFC after:	1 week
2013-09-05 14:16:37 +00:00
Andrey V. Elsukov
d983befd2f Remove unused code and sort variables declarations.
PR:		kern/181822
MFC after:	1 week
2013-09-05 08:12:36 +00:00
Andrey V. Elsukov
5b7cb97c2b Migrate structs arpstat, icmpstat, mrtstat, pimstat and udpstat to PCPU
counters.
2013-07-09 09:50:15 +00:00
Xin LI
f2297451fe Fix incomplete printf.
PR:		kern/177889
Submitted by:	Sven-Thorsten Dietrich <sven vyatta com>
MFC after:	1 week
2013-04-16 19:32:12 +00:00
Xin LI
c1031303f0 Don't leak lock when returning.
PR:		kern/177888
Submitted by:	Sven-Thorsten Dietrich <sven vyatta com>
MFC after:	1 week
2013-04-16 19:25:41 +00:00
Gleb Smirnoff
dc4ad05ecd Use m_get/m_gethdr instead of compat macros.
Sponsored by:	Nginx, Inc.
2013-03-15 12:55:30 +00:00
Gleb Smirnoff
eb1b1807af Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually
2012-12-05 08:04:20 +00:00
Gleb Smirnoff
078468ede4 o Remove last argument to ip_fragment(), and obtain all needed information
on checksums directly from mbuf flags. This simplifies code.
o Clear CSUM_IP from the mbuf in ip_fragment() if we did checksums in
  hardware. Some driver may not announce CSUM_IP in theur if_hwassist,
  although try to do checksums if CSUM_IP set on mbuf. Example is em(4).
o While here, consistently use CSUM_IP instead of its alias CSUM_DELAY_IP.
  After this change CSUM_DELAY_IP vanishes from the stack.

Submitted by:	Sebastian Kuzminsky <seb lineratesystems.com>
2012-10-26 21:06:33 +00:00
Gleb Smirnoff
8f134647ca Switch the entire IPv4 stack to keep the IP packet header
in network byte order. Any host byte order processing is
done in local variables and host byte order values are
never[1] written to a packet.

  After this change a packet processed by the stack isn't
modified at all[2] except for TTL.

  After this change a network stack hacker doesn't need to
scratch his head trying to figure out what is the byte order
at the given place in the stack.

[1] One exception still remains. The raw sockets convert host
byte order before pass a packet to an application. Probably
this would remain for ages for compatibility.

[2] The ip_input() still subtructs header len from ip->ip_len,
but this is planned to be fixed soon.

Reviewed by:	luigi, Maxim Dounin <mdounin mdounin.ru>
Tested by:	ray, Olivier Cochard-Labbe <olivier cochard.me>
2012-10-22 21:09:03 +00:00
Kevin Lo
9823d52705 Revert previous commit...
Pointyhat to:	kevlo (myself)
2012-10-10 08:36:38 +00:00
Kevin Lo
a10cee30c9 Prefer NULL over 0 for pointers 2012-10-09 08:27:40 +00:00
Gleb Smirnoff
23e9c6dc1e After r241245 it appeared that in_delayed_cksum(), which still expects
host byte order, was sometimes called with net byte order. Since we are
moving towards net byte order throughout the stack, the function was
converted to expect net byte order, and its consumers fixed appropriately:
  - ip_output(), ipfilter(4) not changed, since already call
    in_delayed_cksum() with header in net byte order.
  - divert(4), ng_nat(4), ipfw_nat(4) now don't need to swap byte order
    there and back.
  - mrouting code and IPv6 ipsec now need to switch byte order there and
    back, but I hope, this is temporary solution.
  - In ipsec(4) shifted switch to net byte order prior to in_delayed_cksum().
  - pf_route() catches up on r241245 changes to ip_output().
2012-10-08 08:03:58 +00:00
Gleb Smirnoff
3df6468a2d Remove route caching from IP multicast routing code. There is no
reason to do that, and also, cached route never got unreferenced,
which meant a reference leak.

Reviewed by:	bms
2012-07-02 19:44:18 +00:00
Marko Zec
1c7792950c Change SYSINIT priorities so that ip_mroute_modevent() is executed
before vnet_mroute_init(), since vnet_mroute_init() depends on mfchashsize
tunable to be set, and that is done in in ip_mroute_modevent().
Apparently I broke that ordering with r208744 almost 2 years ago...

PR:		kern/162201
Submitted by:	Stevan Markovic (mcafee.com)
MFC after:	3 days
2012-03-04 18:59:38 +00:00
Ed Schouten
6472ac3d8a Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
2011-11-07 15:43:11 +00:00
Dimitry Andric
3e288e6238 After some off-list discussion, revert a number of changes to the
DPCPU_DEFINE and VNET_DEFINE macros, as these cause problems for various
people working on the affected files.  A better long-term solution is
still being considered.  This reversal may give some modules empty
set_pcpu or set_vnet sections, but these are harmless.

Changes reverted:

------------------------------------------------------------------------
r215318 | dim | 2010-11-14 21:40:55 +0100 (Sun, 14 Nov 2010) | 4 lines

Instead of unconditionally emitting .globl's for the __start_set_xxx and
__stop_set_xxx symbols, only emit them when the set_vnet or set_pcpu
sections are actually defined.

------------------------------------------------------------------------
r215317 | dim | 2010-11-14 21:38:11 +0100 (Sun, 14 Nov 2010) | 3 lines

Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.

------------------------------------------------------------------------
r215316 | dim | 2010-11-14 21:23:02 +0100 (Sun, 14 Nov 2010) | 2 lines

Add macros to define static instances of VNET_DEFINE and DPCPU_DEFINE.
2010-11-22 19:32:54 +00:00
Dimitry Andric
31c6a0037e Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.
2010-11-14 20:38:11 +00:00
Marko Zec
7c4b8137cd Virtualize the IPv4 multicast routing code.
Submitted by:	iprebeg
Reviewed by:	bms, bz, Pavlin Radoslavov
MFC after:	30 days
2010-06-02 15:44:43 +00:00
Pawel Jakub Dawidek
957d68dd91 No need to include security/mac/mac_framework.h here. 2010-02-18 22:26:01 +00:00
Shteryana Shopova
7c90b0258f Make sure the multicast forwarding cache entry's stall queue is properly
initialized before trying to insert an entry into it.

PR:		kern/142052
Reviewed by:	bms
MFC after:	now
2009-12-30 08:52:13 +00:00
Bruce M Simpson
6cbbe26f98 In expire_mfc(), add an assert on the multicast forwarding cache mutex.
PR:		138666
2009-09-13 01:00:24 +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
Robert Watson
8c0fec805f Modify most routines returning 'struct ifaddr *' to return references
rather than pointers, requiring callers to properly dispose of those
references.  The following routines now return references:

  ifaddr_byindex
  ifa_ifwithaddr
  ifa_ifwithbroadaddr
  ifa_ifwithdstaddr
  ifa_ifwithnet
  ifaof_ifpforaddr
  ifa_ifwithroute
  ifa_ifwithroute_fib
  rt_getifa
  rt_getifa_fib
  IFP_TO_IA
  ip_rtaddr
  in6_ifawithifp
  in6ifa_ifpforlinklocal
  in6ifa_ifpwithaddr
  in6_ifadd
  carp_iamatch6
  ip6_getdstifaddr

Remove unused macro which didn't have required referencing:

  IFP_TO_IA6

This closes many small races in which changes to interface
or address lists while an ifaddr was in use could lead to use of freed
memory (etc).  In a few cases, add missing if_addr_list locking
required to safely acquire references.

Because of a lack of deep copying support, we accept a race in which
an in6_ifaddr pointed to by mbuf tags and extracted with
ip6_getdstifaddr() doesn't hold a reference while in transmit.  Once
we have mbuf tag deep copy support, this can be fixed.

Reviewed by:	bz
Obtained from:	Apple, Inc. (portions)
MFC after:	6 weeks (portions)
2009-06-23 20:19:09 +00:00
Roman Divacky
e40bae9a45 Switch cmd argument to u_long. This matches what if_ethersubr.c does and
allows the code to compile cleanly on amd64 with clang.

Reviewed by:	rwatson
Approved by:	ed (mentor)
2009-06-21 10:29:31 +00:00
Robert Watson
bcf11e8d00 Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with:	pjd
2009-06-05 14:55:22 +00:00
Bruce M Simpson
5cf93e5d2c Use KTR_INET for MROUTING CTRs. 2009-04-29 10:17:08 +00:00
Marko Zec
093f25f8c8 In preparation for turning on options VIMAGE in next commits,
rearrange / replace / adjust several INIT_VNET_* initializer
macros, all of which currently resolve to whitespace.

Reviewed by:	bz (an older version of the patch)
Approved by:	julian (mentor)
2009-04-26 22:06:42 +00:00
Robert Watson
07cf7ab29c Update stats in struct pimstat using two new macros: PIMSTAT_ADD()
and PIMSTAT_INC(), rather than directly manipulating the fields of
the structure.  This will make it easier to change the
implementation of these statistics, such as using per-CPU versions
of the data structure.

MFC after:	3 days
2009-04-12 14:06:26 +00:00
Robert Watson
fb83a36856 Update stats in struct mrtstat using two new macros: MRTSTAT_ADD()
and MRTSTAT_INC(), rather than directly manipulating the fields of
the structure.  This will make it easier to change the
implementation of these statistics, such as using per-CPU versions
of the data structure.

MFC after:	3 days
2009-04-12 14:00:36 +00:00
Bruce M Simpson
545dff6fd1 Fix brainos introduced during mechanical KTR change.
Pointy hat to:	bms
2009-03-20 13:13:50 +00:00
Bruce M Simpson
98b59af731 Cleanup: Nuke debug.mrtdebug, and replace it with KTR. 2009-03-19 14:14:21 +00:00
Bruce M Simpson
443fc3176d Introduce a number of changes to the MROUTING code.
This is purely a forwarding plane cleanup; no control plane
code is involved.

Summary:
 * Split IPv4 and IPv6 MROUTING support. The static compile-time
   kernel option remains the same, however, the modules may now
   be built for IPv4 and IPv6 separately as ip_mroute_mod and
   ip6_mroute_mod.
 * Clean up the IPv4 multicast forwarding code to use BSD queue
   and hash table constructs. Don't build our own timer abstractions
   when ratecheck() and timevalclear() etc will do.
 * Expose the multicast forwarding cache (MFC) and virtual interface
   table (VIF) as sysctls, to reduce netstat's dependence on libkvm
   for this information for running kernels.
   * bandwidth meters however still require libkvm.
 * Make the MFC hash table size a boot/load-time tunable ULONG,
   net.inet.ip.mfchashsize (defaults to 256).
 * Remove unused members from struct vif and struct mfc.
 * Kill RSVP support, as no current RSVP implementation uses it.
   These stubs could be moved to raw_ip.c.
 * Don't share locks or initialization between IPv4 and IPv6.
 * Don't use a static struct route_in6 in ip6_mroute.c.
   The v6 code is still using a cached struct route_in6, this is
   moved to mif6 for the time being.
 * More cleanup remains to be merged from ip_mroute.c to ip6_mroute.c.

v4 path tested using ports/net/mcast-tools.
v6 changes are mostly mechanical locking and *have not* been tested.
As these changes partially break some kernel ABIs, they will not
be MFCed. There is a lot more work to be done here.

Reviewed by:	Pavlin Radoslavov
2009-03-19 01:43:03 +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
Marko Zec
8b615593fc Step 1.5 of importing the network stack virtualization infrastructure
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
2008-10-02 15:37:58 +00:00
Julian Elischer
ac957cd271 A bunch of formatting fixes brough to light by, or created by the Vimage commit
a few days ago.
2008-08-20 01:05:56 +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
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