bpf: Make BPF interop consistent with if_loop

The pseudo_AF_HDRCMPLT check is already being done in if_loop and
just needed to be ported over to if_ic, if_wg, if_disc, if_gif,
if_gre, if_me, if_tuntap and ng_iface. This is needed in order to
allow these interfaces to work properly with e.g., tcpreplay.

PR: 256587
Reviewed by: markj
MFC after: 2 weeks
Pull Request: https://github.com/freebsd/freebsd-src/pull/876

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

ifnet/API: Move struct ifnet definition to a <net/if_private.h>

Hide the ifnet structure definition, no user serviceable parts inside,
it's a netstack implementation detail. Include it temporarily in
<net/if_var.h> until all drivers are updated to use the accessors
exclusively.

Reviewed by: glebius
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D38046

routing: Allow using IPv6 next-hops for IPv4 routes (RFC 5549).

Implement kernel support for RFC 5549/8950.

* Relax control plane restrictions and allow specifying IPv6 gateways
for IPv4 routes. This behavior is controlled by the
net.route.rib_route_ipv6_nexthop sysctl (on by default).

* Always pass final destination in ro->ro_dst in ip_forward().

* Use ro->ro_dst to exract packet family inside if_output() routines.
Consistently use RO_GET_FAMILY() macro to handle ro=NULL case.

* Pass extracted family to nd6_resolve() to get the LLE with proper encap.
It leverages recent lltable changes committed in c541bd368f86.

Presence of the functionality can be checked using ipv4_rfc5549_support feature(3).
Example usage:
route add -net 192.0.0.0/24 -inet6 fe80::5054:ff:fe14:e319%vtnet0

Differential Revision: https://reviews.freebsd.org/D30398
MFC after: 2 weeks

gre: simplify RSS ifdefs

Use the early break to avoid else definitions. When RSS gains a
runtime option previous constructs would duplicate and convolute
the existing code.

While here init flowid and skip magic numbers and late default
assignment.

Reviewed by: melifaro, kbowling
Obtained from: OPNsense
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D31584

Add if_reassing method to all tunneling interfaces.

After r339550 tunneling interfaces have started handle appearing and
disappearing of ingress IP address on the host system.
When such interfaces are moving into VNET jail, they lose ability to
properly handle ifaddr_event_ext event. And this leads to need to
reconfigure tunnel to make it working again.

Since moving an interface into VNET jail leads to removing of all IP
addresses, it looks consistent, that tunnel configuration should also
be cleared. This is what will do if_reassing method.

Reported by: John W. O'Brien <john saltant com>
MFC after: 1 week

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718

Introduce NET_EPOCH_CALL() macro and use it everywhere where we free
data based on the network epoch. The macro reverses the argument
order of epoch_call(9) - first function, then its argument. NFC

Add GRE-in-UDP encapsulation support as defined in RFC8086.

This GRE-in-UDP encapsulation allows the UDP source port field to be
used as an entropy field for load-balancing of GRE traffic in transit
networks. Also most of multiqueue network cards are able distribute
incoming UDP datagrams to different NIC queues, while very little are
able do this for GRE packets.

When an administrator enables UDP encapsulation with command
`ifconfig gre0 udpencap`, the driver creates kernel socket, that binds
to tunnel source address and after udp_set_kernel_tunneling() starts
receiving of all UDP packets destined to 4754 port. Each kernel socket
maintains list of tunnels with different destination addresses. Thus
when several tunnels use the same source address, they all handled by
single socket. The IP[V6]_BINDANY socket option is used to be able bind
socket to source address even if it is not yet available in the system.
This may happen on system boot, when gre(4) interface is created before
source address become available. The encapsulation and sending of packets
is done directly from gre(4) into ip[6]_output() without using sockets.

Reviewed by: eugen
MFC after: 1 month
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D19921

Add handling for appearing/disappearing of ingress addresses to if_gre(4).

* register handler for ingress address appearing/disappearing;
* add new srcaddr hash table for fast softc lookup by srcaddr;
* when srcaddr disappears, clear IFF_DRV_RUNNING flag from interface,
and set it otherwise;

MFC after: 1 month
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D17214

Fix exiting an epoch(9) we never entered. May happen only with MAC.

Restore outbound packets capturing for if_gre(4). It was missed in r335048.
Also clear M_MCAST and M_BCAST flags for encapsulated datagram, since it
will have new IP header.

Approved by: re (kib)

Use the new VNET_DEFINE_STATIC macro when we are defining static VNET
variables.

Reviewed by: bz
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D16147

Deduplicate the code.

Add generic function if_tunnel_check_nesting() that does check for
allowed nesting level for tunneling interfaces and also does loop
detection. Use it in gif(4), gre(4) and me(4) interfaces.

Differential Revision: https://reviews.freebsd.org/D16162

Rework if_gre(4) to use encap_lookup_t method to speedup lookup
of needed interface when many gre interfaces are present.

Remove rmlock from gre_softc, use epoch(9) and CK_LIST instead.
Move more AF-related code into AF-related locations. Use hash table to
speedup lookup of needed softc.

Rework IP encapsulation handling code.

Currently it has several disadvantages:
- it uses single mutex to protect internal structures. It is used by
data- and control- path, thus there are no parallelism at all.
- it uses single list to keep encap handlers for both INET and INET6
families.
- struct encaptab keeps unneeded information (src, dst, masks, protosw),
that isn't used by code in the source tree.
- matches are prioritized and when many tunneling interfaces are
registered, encapcheck handler of each interface is invoked for each
packet. The search takes O(n) for n interfaces. All this work is done
with exclusive lock held.

What this patch includes:
- the datapath is converted to be lockless using epoch(9) KPI.
- struct encaptab now linked using CK_LIST.
- all unused fields removed from struct encaptab. Several new fields
addedr: min_length is the minimum packet length, that encapsulation
handler expects to see; exact_match is maximum number of bits, that
can return an encapsulation handler, when it wants to consume a packet.
- IPv6 and IPv4 handlers are stored in separate lists;
- added new "encap_lookup_t" method, that will be used later. It is
targeted to speedup lookup of needed interface, when gif(4)/gre(4) have
many interfaces.
- the need to use protosw structure is eliminated. The only pr_input
method was used from this structure, so I don't see the need to keep
using it.
- encap_input_t method changed to avoid using mbuf tags to store softc
pointer. Now it is passed directly trough encap_input_t method.
encap_getarg() funtions is removed.
- all sockaddr structures and code that uses them removed. We don't have
any code in the tree that uses them. All consumers use encap_attach_func()
method, that relies on invoking of encapcheck() to determine the needed
handler.
- introduced struct encap_config, it contains parameters of encap handler
that is going to be registered by encap_attach() function.
- encap handlers are stored in lists ordered by exact_match value, thus
handlers that need more bits to match will be checked first, and if
encapcheck method returns exact_match value, the search will be stopped.
- all current consumers changed to use new KPI.

Reviewed by: mmacy
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D15617

Use an accessor function to access ifr_data.

This fixes 32-bit compat (no ioctl command defintions are required
as struct ifreq is the same size). This is believed to be sufficent to
fully support ifconfig on 32-bit systems.

Reviewed by: kib
Obtained from: CheriBSD
MFC after: 1 week
Relnotes: yes
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14900

sys: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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

No functional change intended.

Do not adjust interface MTU automatically. Leave this task to the system
administrator.

This restores the behavior that was prior to r274246.

No objection from: #network
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D10215

Cleanup unnecessary semicolons from the kernel.

Found with devel/coccinelle.

Wrap using #ifdef 'notyet' those variables and statements not yet
implemented to lower the compiler warnings.

It fix the case of unused-but-set-variable spotted by gcc4.9.

Reviewed by: ngie, ae
Approved by: bapt (mentor)
Differential Revision: https://reviews.freebsd.org/D4720

Check the size of data available in mbuf, before using them.

PR: 202667
MFC after: 1 week

Add IFCAP_LINKSTATE support.

Always detach encap handler when reconfiguring tunnel.

Reported by: hrs
MFC after: 1 week

Add new socket ioctls SIOC[SG]TUNFIB to set FIB number of encapsulated
packets on tunnel interfaces. Add support of these ioctls to gre(4),
gif(4) and me(4) interfaces. For incoming packets M_SETFIB() should use
if_fib value from ifnet structure, use proper value in gre(4) and me(4).

Differential Revision: https://reviews.freebsd.org/D2462
No objection from: #network
MFC after: 2 weeks
Sponsored by: Yandex LLC

Fix an error introduced in r274246.
Pass mtag argument into m_tag_locate() to continue the search from
the last found mtag.

X-MFC after: r274246

Extern declarations in C files loses compile-time checking that
the functions' calls match their definitions. Move them to header files.

Reviewed by: jilles (previous version)

Replace 'struct route *' if_output() argument with 'struct nhop_info *'.
Leave 'struct route' as is for legacy routing api users.
Remove most of rtalloc_ign*-derived functions.

After r274246 make the tree compile again.

gcc requires variables to be initialised in two places. One of them
is correctly used only under the same conditional though.

For module builds properly check if the kernel supports INET or INET6,
as otherwise various mips kernels without IPv6 support would fail to build.

Overhaul if_gre(4).

Split it into two modules: if_gre(4) for GRE encapsulation and
if_me(4) for minimal encapsulation within IP.

gre(4) changes:
* convert to if_transmit;
* rework locking: protect access to softc with rmlock,
protect from concurrent ioctls with sx lock;
* correct interface accounting for outgoing datagramms (count only payload size);
* implement generic support for using IPv6 as delivery header;
* make implementation conform to the RFC 2784 and partially to RFC 2890;
* add support for GRE checksums - calculate for outgoing datagramms and check
for inconming datagramms;
* add support for sending sequence number in GRE header;
* remove support of cached routes. This fixes problem, when gre(4) doesn't
work at system startup. But this also removes support for having tunnels with
the same addresses for inner and outer header.
* deprecate support for various GREXXX ioctls, that doesn't used in FreeBSD.
Use our standard ioctls for tunnels.

me(4):
* implementation conform to RFC 2004;
* use if_transmit;
* use the same locking model as gre(4);

PR: 164475
Differential Revision: D1023
No objections from: net@
Relnotes: yes
Sponsored by: Yandex LLC

Hide 'struct rtentry' and all its macro inside new header:
net/route_internal.h
The goal is to make its opaque for all code except route/rtsock and
proto domain _rmx.

Switch IPv4 output path to use new routing api.

The goals of the new API is to provide consumers with minimal
needed information, but as fast as possible. So we provide
full nexthop info copied into alighed on-cache structure
instead of rte/ia pointers, their refcounts and locks.
This does not provide solution for protecting from egress
ifp destruction, but does not make it any worse.

Current changes:

nhops:
Add fib4_lookup_prepend() function which stores either full
L2+L3 prepend info (e.g. MAC header in case of plain IPv4) or
L3 info with NH_FLAGS_L2_INCOMPLETE flag indicating that no valid L2
info exists and we have to take "slow" path.

ip_output:
Currently ip[ 46]_output consumers use 'struct route' for
the following purposes:
1) double lookup avoidance(route caching)
2) plain route caching
3) get path MTU to be able to notify source.
The former pattern is mostly used by various tunnels
(gif, gre, stf). (Actually, gre is the only remaining,
others were already converted. Their locking model did
not scale good enogh to benefit from such caching, so
we have (temporarily) removed it without any performance
loss).
Plain route caching used by SCTP is simply wrong and should be removed.
Temporary break it for now just to be able to compile.
Optimize path mtu reporting by providing it in new 'route_info' stucture.

Minimize games with @ia locking/refcounting for route lookup:
add special nhop[46]_extended structure to store more route attributes.
Pointer to given structure can be passed to fib4_lookup_prepend() to indicate
we want this info (we actually needs it for UDP and raw IP).

ether_output:
Provide light-weight ether_output2() call to deal with
transmitting L2 frame (e.g. properly handle broadcast/simloop/bridge/
other L2 hooks before actually transmitting frame by if_transmit()).
Add a hack based on new RT_NHOP ro_flag to distinguish which version should
we call. Better way is probably to add a new "if_output_frame" driver
callbacks.

Next steps:
* Convert ip_fastfwd part
* Implement auto-growing array for per-radix nexthops
* Implement LLE tracking for nexthop calculations to be able to
immediately provide all necessary info in single route lookup
for gateway routes
* Switch radix locking scheme to runtime/cfg lock
* Implement multipath support for rtsock
* Implement "tracked nexthops" for tunnels (e.g. _proper_
nexthop caching)
* Add IPv6 support for remaining parts (postponed not to
interfere with user/ae/inet6 branch)
* Consider adding "if_output_frame" driver call to
ease logical frame pushing.

- Virtualize interface cloner for gre(4). This fixes a panic when destroying
a vnet jail which has a gre(4) interface.

- Make net.link.gre.max_nesting vnet-local.

Mechanically convert to if_inc_counter().

Increase errors, not queue drops, in cases the module is supplied
with a bad packet or if mbuf allocation failes.

Change pr_output's prototype to avoid the need for explicit casts.
This is a follow up to r269699.

Phabric: D564
Reviewed by: jhb

Remove AppleTalk support.

AppleTalk was a network transport protocol for Apple Macintosh devices
in 80s and then 90s. Starting with Mac OS X in 2000 the AppleTalk was
a legacy protocol and primary networking protocol is TCP/IP. The last
Mac OS X release to support AppleTalk happened in 2009. The same year
routing equipment vendors (namely Cisco) end their support.

Thus, AppleTalk won't be supported in FreeBSD 11.0-RELEASE.

Remove never used ioctls that originate from KAME. The proof
of their zero usage was exp-run from misc/183538.

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.

Clean up SIOCSIFDSTADDR usage from ifnet drivers. The ioctl itself is
extremely outdated, and I doubt that it was ever used for ifnet drivers.
It was used for AF_INET sockets in pre-FreeBSD time.

Approved by: re (hrs)
Sponsored by: Nginx, Inc.

Add IFF_MONITOR support to gre(4).

Tested by: Chip Marshall
MFC after: 1 week

Add const qualifier to the dst parameter of the ifnet if_output method.

Use m_get/m_gethdr instead of compat macros.

Sponsored by: Nginx, Inc.

Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually

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>

Mechanically remove the last stray remains of spl* calls from net*/*.
They have been Noop's for a long time now.

Make the "struct if_clone" opaque to users of the cloning API. Users
now use function calls:

if_clone_simple()
if_clone_advanced()

to initialize a cloner, instead of macros that initialize if_clone
structure.

Discussed with: brooks, bz, 1 year ago

Revert previous commit...

Pointyhat to: kevlo (myself)

Prefer NULL over 0 for pointers

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.

gre(4) was using a field in the softc to detect possible recursion.
On MP systems this is not a usable solution anymore and could easily
lead to false positives triggering enough logging that even using
the console was no longer usable (multiple parallel ping -f can do).

Switch to the suggested solution of using mbuf tags to carry per
packet state between gre_output() invocations. Contrary to the
proposed solution modelled after gif(4) only allocate one mbuf tag
per packet rather than per packet and per gre_output() pass through.

As the sysctl to control the possible valid (gre in gre) nestings does
no sanity checks, make sure to always allocate space in the mbuf tag
for at least one, and at most 255 possible gre interfaces to detect
loops in addition to the counter.

Submitted by: Cristian KLEIN (cristi net.utcluj.ro) (original version)
PR: kern/114714
Reviewed by: Cristian KLEIN (cristi net.utcluj.ro)
Reviewed bu: Wooseog Choi (ben_choi hotmail.com)
Sponsored by: Sandvine Incorporated
MFC after: 1 week

Hide the outer IP addresses of a tunnel interfaces (gif(4), gre(4))
from processes inside jails if the addresses do not belong to the jail.

Originally reported by: Pieter de Boer via remko
PR: kern/151119
Tested by: Piotr KUCHARSKI (nospam 42.pl) [gif]
MFC after: 1 week

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Add new tunable 'net.link.ifqmaxlen' to set default send interface
queue length. The default value for this parameter is 50, which is
quite low for many of today's uses and the only way to modify this
parameter right now is to edit if_var.h file. Also add read-only
sysctl with the same name, so that it's possible to retrieve the
current value.

MFC after: 1 month

The NetBSD Foundation has granted permission to remove clause 3 and 4 from
their software.

Obtained from: NetBSD

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)

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)

Add the explicit include of vimage.h to another five .c files still
missing it.

Remove the "hidden" kernel only include of vimage.h from ip_var.h added
with the very first Vimage commit r181803 to avoid further kernel poisoning.

Change if_output to take a struct route as its fourth argument in order
to allow passing a cached struct llentry * down to L2

Reviewed by: rwatson

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

- Import the HEAD csup code which is the basis for the cvsmode work.

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

Add support for actually sending WCCP return packets via GRE.
This MAY be combined by a clever person with the 'key' code recently
added, however a cursary glance suggest that it would be safer to just keep
the patches as it is unlikely that the two modes would be used together
and the separate patch has been extensively tested.

Obtained from: here and there
MFC after: 1 week

change a variable name ot stop it from colliding with other names in
some situations. (i.e. in vimage)

MFC after: 1 week

Add support for the optional key in the GRE header.

PR: kern/114714
Submitted by: Cristian KLEIN

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

Replace really convoluted code that simplifies to "a ^= 0x01;"

Sync comments to code: we now use priv_check() rather than suser() to
determine privilege.

Approved by: re (bmah)

Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
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>

With exception of the if_name() macro, all definitions in net_osdep.h
were unused or already in if_var.h so add if_name() to if_var.h and
remove net_osdep.h along with all references to it.

Longer term we may want to kill off if_name() entierly since all modern
BSDs have if_xname variables rendering it unnecessicary.

Revise network interface cloning to take an optional opaque
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@

Fix the following bpf(4) race condition which can result in a panic:

(1) bpf peer attaches to interface netif0
(2) Packet is received by netif0
(3) ifp->if_bpf pointer is checked and handed off to bpf
(4) bpf peer detaches from netif0 resulting in ifp->if_bpf being
initialized to NULL.
(5) ifp->if_bpf is dereferenced by bpf machinery
(6) Kaboom

This race condition likely explains the various different kernel panics
reported around sending SIGINT to tcpdump or dhclient processes. But really
this race can result in kernel panics anywhere you have frequent bpf attach
and detach operations with high packet per second load.

Summary of changes:

- Remove the bpf interface's "driverp" member
- When we attach bpf interfaces, we now set the ifp->if_bpf member to the
bpf interface structure. Once this is done, ifp->if_bpf should never be
NULL. [1]
- Introduce bpf_peers_present function, an inline operation which will do
a lockless read bpf peer list associated with the interface. It should
be noted that the bpf code will pickup the bpf_interface lock before adding
or removing bpf peers. This should serialize the access to the bpf descriptor
list, removing the race.
- Expose the bpf_if structure in bpf.h so that the bpf_peers_present function
can use it. This also removes the struct bpf_if; hack that was there.
- Adjust all consumers of the raw if_bpf structure to use bpf_peers_present

Now what happens is:

(1) Packet is received by netif0
(2) Check to see if bpf descriptor list is empty
(3) Pickup the bpf interface lock
(4) Hand packet off to process

From the attach/detach side:

(1) Pickup the bpf interface lock
(2) Add/remove from bpf descriptor list

Now that we are storing the bpf interface structure with the ifnet, there is
is no need to walk the bpf interface list to locate the correct bpf interface.
We now simply look up the interface, and initialize the pointer. This has a
nice side effect of changing a bpf interface attach operation from O(N) (where
N is the number of bpf interfaces), to O(1).

[1] From now on, we can no longer check ifp->if_bpf to tell us whether or
not we have any bpf peers that might be interested in receiving packets.

In collaboration with: sam@
MFC after: 1 month

Correct test for fragmented packet.

Remove two unnecessary type casts, of which both had a typo in
it anyways.

Approved by: andre
MFC after: 3 days

Fix stack corruptions on amd64.

Vararg functions have a different calling convention than regular
functions on amd64. Casting a varag function to a regular one to
match the function pointer declaration will hide the varargs from
the caller and we will end up with an incorrectly setup stack.

Entirely remove the varargs from these functions and change the
functions to match the declaration of the function pointers.
Remove the now unnecessary casts.

Lots of explanations and help from: peter
Reviewed by: peter
PR: amd64/89261
MFC after: 6 days

Use sparse initializers for "struct domain" and "struct protosw",
so they are easier to follow for the human being.

Move the cloned interface list management in to if_clone. For some drivers the
softc lists and associated mutex are now unused so these have been removed.

Calling if_clone_detach() will now destroy all the cloned interfaces for the
driver and in most cases is all thats needed to unload.

Idea by: brooks
Reviewed by: brooks

Retire MT_HEADER mbuf type and change its users to use MT_DATA.

Having an additional MT_HEADER mbuf type is superfluous and redundant
as nothing depends on it. It only adds a layer of confusion. The
distinction between header mbuf's and data mbuf's is solely done
through the m->m_flags M_PKTHDR flag.

Non-native code is not changed in this commit. For compatibility
MT_HEADER is mapped to MT_DATA.

Sponsored by: TCP/IP Optimization Fundraise 2005

Change the reference counting to count the number of cloned interfaces for each
cloner. This ensures that ifc->ifc_units is not prematurely freed in
if_clone_detach() before the clones are destroyed, resulting in memory modified
after free. This could be triggered with if_vlan.

Assert that all cloners have been destroyed when freeing the memory.

Change all simple cloners to destroy their clones with ifc_simple_destroy() on
module unload so the reference count is properly updated. This also cleans up
the interface destroy routines and allows future optimisation.

Discussed with: brooks, pjd, -current
Reviewed by: brooks

Propagate rename of IFF_OACTIVE and IFF_RUNNING to IFF_DRV_OACTIVE and
IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to
ifnet.if_drv_flags. Device drivers are now responsible for
synchronizing access to these flags, as they are in if_drv_flags. This
helps prevent races between the network stack and device driver in
maintaining the interface flags field.

Many __FreeBSD__ and __FreeBSD_version checks maintained and continued;
some less so.

Reviewed by: pjd, bz
MFC after: 7 days

Add support for IPv6 over GRE [1]. PR kern/80340 includes the
FreeBSD specific ip_newid() changes NetBSD does not have.
Correct handling of non AF_INET packets passed to bpf [2].

PR: kern/80340[1], NetBSD PRs 29150[1], 30844[2]
Obtained from: NetBSD ip_gre.c rev. 1.34,1.35, if_gre.c rev. 1.56
Submitted by: Gert Doering <gert at greenie.muc.de>[2]
MFC after: 4 days

Fix panic after ifnet changes in rev. 1.30. sc->sc_ifp is a
pointer now and needs to be allocated before using.

Reviewed by: gnn
Approved by: re (scottl), rwatson (mentor)

Fix some long standing bugs in writing to the BPF device attached to
a DLT_NULL interface. In particular:

1) Consistently use type u_int32_t for the header of a
DLT_NULL device - it continues to represent the address
family as always.
2) In the DLT_NULL case get bpf_movein to store the u_int32_t
in a sockaddr rather than in the mbuf, to be consistent
with all the DLT types.
3) Consequently fix a bug in bpf_movein/bpfwrite which
only permitted packets up to 4 bytes less than the MTU
to be written.
4) Fix all DLT_NULL devices to have the code required to
allow writing to their bpf devices.
5) Move the code to allow writing to if_lo from if_simloop
to looutput, because it only applies to DLT_NULL devices
but was being applied to other devices that use if_simloop
possibly incorrectly.

PR: 82157
Submitted by: Matthew Luckie <mjl@luckie.org.nz>
Approved by: re (scottl)

Stop embedding struct ifnet at the top of driver softcs. Instead the
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
- Struct arpcom is no longer referenced in normal interface code.
Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
To enforce this ac_enaddr has been renamed to _ac_enaddr.
- The second argument to ether_ifattach is now always the mac address
from driver private storage rather than sometimes being ac_enaddr.

Reviewed by: sobomax, sam

/* -> /*- for license, minor formatting changes

Set ip_v field properly.

PR: kern/69957

Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".

Use M_ZERO instead of memset() (!).

Major overhaul of pseudo-interface cloning. Highlights include:

- Split the code out into if_clone.[ch].
- Locked struct if_clone. [1]
- Add a per-cloner match function rather then simply matching names of
the form <name><unit> and <name>.
- Use the match function to allow creation of <interface>.<tag>
vlan interfaces. The old way is preserved unchanged!
- Also the match function to allow creation of stf(4) interfaces named
stf0, stf, or 6to4. This is the only major user visible change in
that "ifconfig stf" creates the interface stf rather then stf0 and
does not print "stf0" to stdout.
- Allow destroy functions to fail so they can refuse to delete
interfaces. Currently, we forbid the deletion of interfaces which
were created in the init function, particularly lo0, pflog0, and
pfsync0. In the case of lo0 this was a panic implementation so it
does not count as a user visiable change. :-)
- Since most interfaces do not need the new functionality, an family of
wrapper functions, ifc_simple_*(), were created to wrap old style
cloner functions.
- The IF_CLONE_INITIALIZER macro is replaced with a new incompatible
IFC_CLONE_INITIALIZER and ifc_simple consumers use IFC_SIMPLE_DECLARE
instead.

Submitted by: Maurycy Pawlowski-Wieronski <maurycy at fouk.org> [1]
Reviewed by: andre, mlaier
Discussed on: net

add missing #include <sys/module.h>

Add the comment of the previous commit to the source file directly.

Requested by: ru

Call ip_output() with IP_FORWARD flag to prevent it from overwriting the
ip_id again. ip_id is already set to the ip_id of the encapsulated packet.

Make a comment about mbuf allocation failures more realistic.

Reviewed by: sobomax

Lock down global variables in if_gre:

- Add gre_mtx to protect global softc list.
- Hold gre_mtx over various list operations (insert, delete).
- Centralize if_gre interface teardown in gre_destroy(), and call this
from modevent unload and gre_clone_destroy().
- Export gre_mtx to ip_gre.c, which walks the gre list to look up gre
interfaces during encapsulation. Add a wonking comment on how we need
some sort of drain/reference count mechanism to keep gre references
alive while in use and simultaneous destroy.

This commit does not lockdown softc data, which follows in a future
commit.

Remove NetBSD'isms (add FreeBSD'isms?), which makes gre(4) working again.

Add support for WCCPv2. It should be enablem manually using link2
ifconfig(8) flag since header for version 2 is the same but IP payload
is prepended with additional 4-bytes field.

Inspired by: Roman Synyuk <roman@univ.kiev.ua>
MFC after: 2 weeks

(whilespace-only)

Kill trailing spaces.

Sync with NetBSD:

if_gre.c rev.1.41-1.49

o Spell output with two ts.
o Remove assigned-to but not used variable.
o fix grammatical error in a diagnostic message.
o u_short -> u_int16_t.
o gi_len is ip_len, so it has to be network byteorder.

if_gre.h rev.1.11-1.13

o prototype must not have variable name.
o u_short -> u_int16_t.
o Spell address with two d's.

ip_gre.c rev.1.22-1.29

o KNF - return is not a function.
o The "osrc" variable in gre_mobile_input() is only ever set but not
referenced; remove it.
o correct (false) assumptions on mbuf chain. not sure if it really helps, but
anyways, it is necessary to perform m_pullup.
o correct arg to m_pullup (need to count IP header size as well).
o remove redundant adjustment of m->m_pkthdr.len.
o clear m_flags just for safety.
o tabify.
o u_short -> u_int16_t.

MFC after: 2 weeks

o eliminate widespread on-stack mbuf use for bpf by introducing
a new bpf_mtap2 routine that does the right thing for an mbuf
and a variable-length chunk of data that should be prepended.
o while we're sweeping the drivers, use u_int32_t uniformly when
when prepending the address family (several places were assuming
sizeof(int) was 4)
o return M_ASSERTVALID to BPF_MTAP* now that all stack-allocated
mbufs have been eliminated; this may better be moved to the bpf
routines

Reviewed by: arch@ and several others

Declare gre(4) as being of IFT_TUNNEL, Like God Intended.

Suggested by: fenner

Fix a bug whereby the physical endpoints of a gre(4) tunnel would not
be printed, if the module were loaded into a kernel which had INET6 enabled.

The gre(4) driver does not use INET6, nor is it specified for IPv6. The
tunnel_status() function in ifconfig(8) is somewhat overzealous and assumes
that all tunnel interfaces speak KAME ifioctls.

This fix follows the path of least resistance, by teaching gre(4) about
the two KAME ifioctls concerned.

PR: bin/56341

Replace the if_name and if_unit members of struct ifnet with new members
if_xname, if_dname, and if_dunit. if_xname is the name of the interface
and if_dname/unit are the driver name and instance.

This change paves the way for interface renaming and enhanced pseudo
device creation and configuration symantics.

Approved By: re (in principle)
Reviewed By: njl, imp
Tested On: i386, amd64, sparc64
Obtained From: NetBSD (if_xname)

Finish driving a stake through the heart of netns and the associated
ifdefs scattered around the place - its dead Jim!

The SMB stuff had stolen AF_NS, make it official.

Back out M_* changes, per decision of the TRB.

Approved by: trb

Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.

network interface and link layer changes:

o on input don't strip the Ethernet header from packets
o input packet handling is now done with if_input
o track changes to ether_ifattach/ether_ifdetach API
o track changes to bpf tapping
o call ether_ioctl for default handling of ioctl's
o use constants from net/ethernet.h where possible

Reviewed by: many
Approved by: re

de-__P()

Replace aux mbufs with packet tags:

o instead of a list of mbufs use a list of m_tag structures a la openbsd
o for netgraph et. al. extend the stock openbsd m_tag to include a 32-bit
ABI/module number cookie
o for openbsd compatibility define a well-known cookie MTAG_ABI_COMPAT and
use this in defining openbsd-compatible m_tag_find and m_tag_get routines
o rewrite KAME use of aux mbufs in terms of packet tags
o eliminate the most heavily used aux mbufs by adding an additional struct
inpcb parameter to ip_output and ip6_output to allow the IPsec code to
locate the security policy to apply to outbound packets
o bump __FreeBSD_version so code can be conditionalized
o fixup ipfilter's call to ip_output based on __FreeBSD_version

Reviewed by: julian, luigi (silent), -arch, -net, darren
Approved by: julian, silence from everyone else
Obtained from: openbsd (mostly)
MFC after: 1 month

Since bpf is no longer an optional component, remove associated ifdef's.

Submitted by: don't quite remember - the name of the sender disappeared
with the rest of my inbox. :(

Remove __RCSID().

Submitted by: bde

Include include "opt_atalk.h" so that the NETATALK support can work.

Removed unused includes.

Removed used includes of <sys/queue.h> and <sys/time.h>, since these are
standard pollution (especially the latter).

Reviewed by: sobomax

Include <sys/systm.h> instead of depending on namespace pollution 2
layers deep in <sys/malloc.h> or 1 layer deep in <net/if_var.h>.

Reduce namespace pollution by staticizing everything, which doesn't need to
be visible from outside of the module.

Add a new gre(4) driver, which could be used to create GRE (RFC1701)
and MOBILE (RFC2004) IP tunnels.

Obrained from: NetBSD