MFC r345560:
Add CTLFLAG_VNET to the net.inet.icmp.tstamprepl definition.

Unbreak build after r340670. This is direct commit to stable/11.

MFC r339558: New sysctl: net.inet.icmp.error_keeptags

Currently, icmp_error() function copies FIB number from original packet
into generated ICMP response but not mbuf_tags(9) chain.
This prevents us from easily matching ICMP responses corresponding
to tagged original packets by means of packet filter such as ipfw(8).
For example, ICMP "time-exceeded in-transit" packets usually generated
in response to traceroute probes lose tags attached to original packets.

This change adds new sysctl net.inet.icmp.error_keeptags
that defaults to 0 to avoid extra overhead when this feature not needed.

Set net.inet.icmp.error_keeptags=1 to make icmp_error() copy mbuf_tags
from original packet to generated ICMP response.

PR: 215874

MFC r340260 (emaste):
Avoid buffer underwrite in icmp_error

icmp_error allocates either an mbuf (with pkthdr) or a cluster depending
on the size of data to be quoted in the ICMP reply, but the calculation
failed to account for the additional padding that m_align may apply.

Include the ip header in the size passed to m_align. On 64-bit archs
this will have the net effect of moving everything 4 bytes later in the
mbuf or cluster. This will result in slightly pessimal alignment for
the ICMP data copy.

Also add an assertion that we do not move m_data before the beginning of
the mbuf or cluster.

Approved by: re (kib, insta-MFC)
Security: CVE-2018-17156
Sponsored by: The FreeBSD Foundation

MFC r319214:
Enforce the limit on ICMP messages before doing work to formulate the
response.

Delete an unneeded rate limit for UDP under IPv6. Because ICMP6
messages have their own rate limit, it is unnecessary to apply a
second rate limit to UDP messages.

Sponsored by: Netflix, Inc.

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

MFC r314568 (by emaste):

kern_sig.c: ANSIfy and remove archaic register keyword

Sponsored by: The FreeBSD Foundation

MFC r318389 (by emaste):

Remove register keyword from sys/ and ANSIfy prototypes

A long long time ago the register keyword told the compiler to store
the corresponding variable in a CPU register, but it is not relevant
for any compiler used in the FreeBSD world today.

ANSIfy related prototypes while here.

Reviewed by: cem, jhb
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D10193

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r324098:
Some mbuf related fixes in icmp_error()

* check mbuf length before doing mtod() and accessing to IP header;
* update oip pointer and all depending pointers after m_pullup();
* remove extra checks and extra parentheses, wrap long lines;

PR: 222670

MFC r313821 r315277 r315286

Use inet_ntoa_r() instead of inet_ntoa() throughout the kernel.

inet_ntoa() cannot be used safely in a multithreaded environment
because it uses a static local buffer. Instead, use inet_ntoa_r()
with a buffer on the caller's stack, except for KTR messages.
KTR can correctly log the immediate integral values passed to it,
as well as constant strings, but not non-constant strings,
since they might change by the time ktrdump retrieves them.
Therefore, use hex notation in KTR messages.

Sponsored by: Dell EMC

MFC r307726:

Make ICMPv6 hard error handling for TCP consistent with the ICMPv4
handling. Ensure that:
* Protocol unreachable errors are handled by indicating ECONNREFUSED
to the TCP user for both IPv4 and IPv6. These were ignored for IPv6.
* Communication prohibited errors are handled by indicating ECONNREFUSED
to the TCP user for both IPv4 and IPv6. These were ignored for IPv6.
* Hop Limited exceeded errors are handled by indicating EHOSTUNREACH
to the TCP user for both IPv4 and IPv6.
For IPv6 the TCP connected was dropped but errno wasn't set.

Sponsored by: Netflix, Inc.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

When sending in ICMP response to an SCTP packet,
* include the SCTP common header, if possible
* include the first 8 bytes of the INIT chunk, if possible
This provides the necesary information for the receiver of the ICMP
packet to process it.

MFC after: 1 week

Fix a few style issues in the ICMP sysctl descriptions.

MFC after: 1 week

sys/net*: minor spelling fixes.

No functional change.

netinet: for pointers replace 0 with NULL.

These are mostly cosmetical, no functional change.

Found with devel/coccinelle.

Reviewed by: ae. tuexen

When delivering an ICMP packet to the ctlinput function, ensure that
the outer IP header, the ICMP header, the inner IP header and the
first n bytes are stored in contgous memory. The ctlinput functions
currently rely on this for n = 8. This fixes a bug in case the inner IP
header had options.
While there, remove the options from the outer header and provide a
way to increase n to allow improved ICMP handling for SCTP. This will
be added in another commit.

MFC after: 1 week

Make in_arpinput(), inp_lookup_mcast_ifp(), icmp_reflect(),
ip_dooptions(), icmp6_redirect_input(), in6_lltable_rtcheck(),
in6p_lookup_mcast_ifp() and in6_selecthlim() use new routing api.

Eliminate now-unused ip_rtaddr().
Fix lookup key fib6_lookup_nh_basic() which was lost diring merge.
Make fib6_lookup_nh_basic() and fib6_lookup_nh_extended() always
return IPv6 destination address with embedded scope. Currently
rw_gateway has it scope embedded, do the same for non-gatewayed
destinations.

Sponsored by: Yandex LLC

Convert in_ifaddr_lock and in6_ifaddr_lock to rmlock.

Both are used to protect access to IP addresses lists and they can be
acquired for reading several times per packet. To reduce lock contention
it is better to use rmlock here.

Reviewed by: gnn (previous version)
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D3149

Where appropriate, use the modern terms for the one true time base
(UTC) rather than the archaic (GMT) in comments. Except where the
comments are making fun of people doing this (and pedants who insist
on the new terms).

Remove route chaching support from ipsec code. It isn't used for some time.
* remove sa_route_union declaration and route_cache member from struct secashead;
* remove key_sa_routechange() call from ICMP and ICMPv6 code;
* simplify ip_ipsec_mtu();
* remove #include <net/route.h>;

Sponsored by: Yandex LLC

Kill custom in_matroute() radix mathing function removing one rte mutex lock.

Initially in_matrote() in_clsroute() in their current state was introduced by
r4105 20 years ago. Instead of deleting inactive routes immediately, we kept them
in route table, setting RTPRF_OURS flag and some expire time. After that, either
GC came or RTPRF_OURS got removed on first-packet. It was a good solution
in that days (and probably another decade after that) to keep TCP metrics.
However, after moving metrics to TCP hostcache in r122922, most of in_rmx
functionality became unused. It might had been used for flushing icmp-originated
routes before rte mutexes/refcounting, but I'm not sure about that.

So it looks like this is nearly impossible to make GC do its work nowadays:

in_rtkill() ignores non-RTPRF_OURS routes.
route can only become RTPRF_OURS after dropping last reference via rtfree()
which calls in_clsroute(), which, it turn, ignores UP and non-RTF_DYNAMIC routes.

Dynamic routes can still be installed via received redirect, but they
have default lifetime (no specific rt_expire) and no one has another trie walker
to call RTFREE() on them.

So, the changelist:
* remove custom rnh_match / rnh_close matching function.
* remove all GC functions
* partially revert r256695 (proto3 is no more used inside kernel,
it is not possible to use rt_expire from user point of view, proto3 support
is not complete)
* Finish r241884 (similar to this commit) and remove remaining IPv6 parts

MFC after: 1 month

Remove kernel handling of ICMP_SOURCEQUENCH.
It hasn't been used for a very long time.
Additionally, it was deprecated by RFC 6633.

Renove faith(4) and faithd(8) from base. It looks like industry
have chosen different (and more traditional) stateless/statuful
NAT64 as translation mechanism. Last non-trivial commits to both
faith(4) and faithd(8) happened more than 12 years ago, so I assume
it is time to drop RFC3142 in FreeBSD.

No objections from: net@

Remove SYSCTL_VNET_* macros, and simply put CTLFLAG_VNET where needed.

Sponsored by: Nginx, Inc.

Add a sysctl, net.inet.icmp.tstamprepl, which can be used to disable replies
to ICMP Timestamp packets.

PR: 193689
Submitted by: Anthony Cornehl <accornehl@gmail.com>
MFC after: 3 weeks
Sponsored by: EMC / Isilon Storage Division

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

Don't copy the MF flag from original IP header to ICMP error message.

PR: 188092
MFC after: 1 week
Sponsored by: Yandex LLC

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.

Migrate structs arpstat, icmpstat, mrtstat, pimstat and udpstat to PCPU
counters.

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

Exceptions:

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

Use ip_stripoptions() instead of handrolled version.

Do not reduce ip_len by size of IP header in the ip_input()
before passing a packet to protocol input routines.
For several protocols this mean that now protocol needs to
do subtraction itself, and for another half this means that
we do not need to add header length back to the packet.

Make ip_stripoptions() to adjust ip_len, since now we enter
this function with a packet header whose ip_len does represent
length of entire packet, not payload only.

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>

Do not check if found IPv4 rte is dynamic if net.inet.icmp.drop_redirect is
enabled. This eliminates one mtx_lock() per each routing lookup thus improving
performance in several cases (routing to directly connected interface or routing
to default gateway).

Icmp redirects should not be used to provide routing direction nowadays, even
for end hosts. Routers should not use them too (and this is explicitly restricted
in IPv6, see RFC 4861, clause 8.2).

Current commit changes rnh_machaddr function to 'stock' rn_match (and back) for every
AF_INET routing table in given VNET instance on drop_redirect sysctl change.

This change is part of bigger patch eliminating rte locking.

Sponsored by: Yandex LLC
MFC after: 2 weeks

Merge the projects/pf/head branch, that was worked on for last six months,
into head. The most significant achievements in the new code:

o Fine grained locking, thus much better performance.
o Fixes to many problems in pf, that were specific to FreeBSD port.

New code doesn't have that many ifdefs and much less OpenBSDisms, thus
is more attractive to our developers.

Those interested in details, can browse through SVN log of the
projects/pf/head branch. And for reference, here is exact list of
revisions merged:

r232043, r232044, r232062, r232148, r232149, r232150, r232298, r232330,
r232332, r232340, r232386, r232390, r232391, r232605, r232655, r232656,
r232661, r232662, r232663, r232664, r232673, r232691, r233309, r233782,
r233829, r233830, r233834, r233835, r233836, r233865, r233866, r233868,
r233873, r234056, r234096, r234100, r234108, r234175, r234187, r234223,
r234271, r234272, r234282, r234307, r234309, r234382, r234384, r234456,
r234486, r234606, r234640, r234641, r234642, r234644, r234651, r235505,
r235506, r235535, r235605, r235606, r235826, r235991, r235993, r236168,
r236173, r236179, r236180, r236181, r236186, r236223, r236227, r236230,
r236252, r236254, r236298, r236299, r236300, r236301, r236397, r236398,
r236399, r236499, r236512, r236513, r236525, r236526, r236545, r236548,
r236553, r236554, r236556, r236557, r236561, r236570, r236630, r236672,
r236673, r236679, r236706, r236710, r236718, r237154, r237155, r237169,
r237314, r237363, r237364, r237368, r237369, r237376, r237440, r237442,
r237751, r237783, r237784, r237785, r237788, r237791, r238421, r238522,
r238523, r238524, r238525, r239173, r239186, r239644, r239652, r239661,
r239773, r240125, r240130, r240131, r240136, r240186, r240196, r240212.

I'd like to thank people who participated in early testing:

Tested by: Florian Smeets <flo freebsd.org>
Tested by: Chekaluk Vitaly <artemrts ukr.net>
Tested by: Ben Wilber <ben desync.com>
Tested by: Ian FREISLICH <ianf cloudseed.co.za>

Add rate limitation for SCTP OOTB responses.

MFC after: 3 days

- Fix sysctl description

PR: 163623
Submitted by: Eugene Grosbein <eugen@eg.sd.rdtc.ru>
Approved by: bz

Convert all users of IF_ADDR_LOCK to use new locking macros that specify
either a read lock or write lock.

Reviewed by: bz
MFC after: 2 weeks

Update packet filter (pf) code to OpenBSD 4.5.

You need to update userland (world and ports) tools
to be in sync with the kernel.

Submitted by: mlaier
Submitted by: eri

MfP4 CH=192029:

Expose ip_icmp.c to INET6 as well and only export badport_bandlim()
along with the two sysctls in the non-INET case.
The bandlim types work for all cases I reviewed in IPv6 as well and
the sysctls are available as we export net.inet.* from in_proto.c.

Reviewed by: gnn
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
MFC after: 4 days

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.

Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.

Change the messages of the ICMP bad port bandwidth limiter from
a kernel printf to a log output with the priority of LOG_NOTICE.

This way the messages still show up in /var/log/messages but no
longer spam the console every other second on busy servers that
are port scanned:
"Limiting open port RST response from 114 to 100 packets/sec"

PR: kern/147352
Submitted by: Eugene Grosbein <eugen-at-eg sd rdtc ru>
MFC after: 1 week

MFP4: @176978-176982, 176984, 176990-176994, 177441

"Whitspace" churn after the VIMAGE/VNET whirls.

Remove the need for some "init" functions within the network
stack, like pim6_init(), icmp_init() or significantly shorten
others like ip6_init() and nd6_init(), using static initialization
again where possible and formerly missed.

Move (most) variables back to the place they used to be before the
container structs and VIMAGE_GLOABLS (before r185088) and try to
reduce the diff to stable/7 and earlier as good as possible,
to help out-of-tree consumers to update from 6.x or 7.x to 8 or 9.

This also removes some header file pollution for putatively
static global variables.

Revert VIMAGE specific changes in ipfilter::ip_auth.c, that are
no longer needed.

Reviewed by: jhb
Discussed with: rwatson
Sponsored by: The FreeBSD Foundation
Sponsored by: CK Software GmbH
MFC after: 6 days

Compare pointer to NULL rather than 0.

MFC after: 1 month

Many network stack subsystems use a single global data structure to hold
all pertinent statatistics for the subsystem. These structures are
sometimes "borrowed" by kernel modules that require a place to store
statistics for similar events.

Add KPI accessor functions for statistics structures referenced by kernel
modules so that they no longer encode certain specifics of how the data
structures are named and stored. This change is intended to make it
easier to move to per-CPU network stats following 8.0-RELEASE.

The following modules are affected by this change:

if_bridge
if_cxgb
if_gif
ip_mroute
ipdivert
pf

In practice, most of these statistics consumers should, in fact, maintain
their own statistics data structures rather than borrowing structures
from the base network stack. However, that change is too agressive for
this point in the release cycle.

Reviewed by: bz
Approved by: re (kib)

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)

Remove unused VNET_SET() and related macros; only VNET_GET() is
ever actually used. Rename VNET_GET() to VNET() to shorten
variable references.

Discussed with: bz, julian
Reviewed by: bz
Approved by: re (kensmith, kib)

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 a new global rwlock, in_ifaddr_lock, which will synchronize use of the
in_ifaddrhead and INADDR_HASH address lists.

Previously, these lists were used unsynchronized as they were effectively
never changed in steady state, but we've seen increasing reports of
writer-writer races on very busy VPN servers as core count has gone up
(and similar configurations where address lists change frequently and
concurrently).

For the time being, use rwlocks rather than rmlocks in order to take
advantage of their better lock debugging support. As a result, we don't
enable ip_input()'s read-locking of INADDR_HASH until an rmlock conversion
is complete and a performance analysis has been done. This means that one
class of reader-writer races still exists.

MFC after: 6 weeks
Reviewed by: bz

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)

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

In icmp_reflect(), acquire the inteface address list lock when
searching for a source address to use.

MFC after: 2 weeks
Reviewed by: bz

Update stats in struct icmpstat and icmp6stat using four new
macros: ICMPSTAT_ADD(), ICMPSTAT_INC(), ICMP6STAT_ADD(), and
ICMP6STAT_INC(), rather than directly manipulating the fields
of these structures across the kernel. This will make it
easier to change the implementation of these statistics,
such as using per-CPU versions of the data structures.

In on case, icmp6stat members are manipulated indirectly, by
icmp6_errcount(), and this will require further work to fix
for per-CPU stats.

MFC after: 3 days

Use uint32_t instead of n_long and n_time, and uint16_t instead of n_short.
Add a note next to fields in network format.

The n_* types are not enough for compiler checks on endianness, and their
use often requires an otherwise unnecessary #include <netinet/in_systm.h>

The typedef in in_systm.h are still there.

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

Change the initialization methodology for global variables scheduled
for virtualization.

Instead of initializing the affected global variables at instatiation,
assign initial values to them in initializer functions. As a rule,
initialization at instatiation for such variables should never be
introduced again from now on. Furthermore, enclose all instantiations
of such global variables in #ifdef VIMAGE_GLOBALS blocks.

Essentialy, this change should have zero functional impact. In the next
phase of merging network stack virtualization infrastructure from
p4/vimage branch, the new initialization methology will allow us to
switch between using global variables and their counterparts residing in
virtualization containers with minimum code churn, and in the long run
allow us to intialize multiple instances of such container structures.

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

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

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

Fix the loopback interface. Cleaning up some code with new macros
was a tad too aggressive.

PR: kern/123568
Submitted by: Vladimir Ermakov <samflanker at gmail dot com>
Obtained from: antoine

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

Add in check for loopback as well, which was missing from the original patch.

PR: 120958
Submitted by: James Snow <snow at teardrop.org>
MFC after: 2 weeks

Clean up the code that checks the types of address so that it is
done by understandable macros.

Fix the bug that prevented the system from responding on interfaces with
link local addresses assigned.

PR: 120958
Submitted by: James Snow <snow at teardrop.org>
MFC after: 2 weeks

Continue to move from generic network entry points in the TrustedBSD MAC
Framework by moving from mac_mbuf_create_netlayer() to more specific
entry points for specific network services:

- mac_netinet_firewall_reply() to be used when replying to in-bound TCP
segments in pf and ipfw (etc).

- Rename mac_netinet_icmp_reply() to mac_netinet_icmp_replyinplace() and
add mac_netinet_icmp_reply(), reflecting that in some cases we overwrite
a label in place, but in others we apply the label to a new mbuf.

Obtained from: TrustedBSD Project

Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

mac_<object>_<method/action>
mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme. Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier. Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods. Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by: SPARTA (original patches against Mac OS X)
Obtained from: TrustedBSD Project, Apple Computer

Add FBSDID to all files in netinet so that people can more
easily include file version information in bug reports.

Approved by: re (kensmith)

Attempt to improve feature parity between UDPv4 and UDPv6 by merging
UDPv4 features to UDPv6:

- Add MAC checks on delivery and MAC labeling on transmit.
- Check for (and reject) datagrams with destination port 0.
- For multicast delivery, check the source port only if the socket being
considered as a destination has been connected.
- Implement UDP blackholing based on net.inet.udp.blackhole.
- Add a new ICMPv6 unreachable reply rate limiting category for failed
delivery attempts and implement rate limiting for UDPv6 (submitted by
bz).

Approved by: re (kensmith)
Reviewed by: bz

Commit the change from FAST_IPSEC to IPSEC. The FAST_IPSEC
option is now deprecated, as well as the KAME IPsec code.
What was FAST_IPSEC is now IPSEC.

Approved by: re
Sponsored by: Secure Computing

Commit IPv6 support for FAST_IPSEC to the tree.
This commit includes only the kernel files, the rest of the files
will follow in a second commit.

Reviewed by: bz
Approved by: re
Supported by: Secure Computing

Move universally to ANSI C function declarations, with relatively
consistent style(9)-ish layout.

Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from: TrustedBSD Project
Sponsored by: SPARTA

Add descriptions for the sysctls:

net.inet.icmp.drop_redirect
net.inet.icmp.log_redirect
net.inet.icmp.icmplim
net.inet.icmp.icmplim_output

Approved & text by: andre

Fix build.

Simplify ip_next_mtu() and make its logic more easy to see while
silencing code analysis tools.

Found by: Coverity Prevent(tm)
Coverity ID: CID341
Sponsored by: TCP/IP Optimization Fundraise 2005

Consolidate all IP Options handling functions into ip_options.[ch] and
include ip_options.h into all files making use of IP Options functions.

From ip_input.c rev 1.306:
ip_dooptions(struct mbuf *m, int pass)
save_rte(m, option, dst)
ip_srcroute(m0)
ip_stripoptions(m, mopt)

From ip_output.c rev 1.249:
ip_insertoptions(m, opt, phlen)
ip_optcopy(ip, jp)
ip_pcbopts(struct inpcb *inp, int optname, struct mbuf *m)

No functional changes in this commit.

Discussed with: rwatson
Sponsored by: TCP/IP Optimization Fundraise 2005

Rework icmp_error() to deal with truncated IP packets from
ip_forward() when doing extended quoting in error messages.

Sponsored by: TCP/IP Optimization Fundraise 2005

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

o Fix a logic error when not doing mbuf cluster allocation.
o Change an old panic() to a clean function exit.

MFC after: 2 weeks
Sponsored by: TCP/IP Optimization Fundraise 2005

Always quote the entire TCP header when responding and allocate an mbuf
cluster if needed.

Fixes the TCP issues raised in I-D draft-gont-icmp-payload-00.txt.

This aids in-the-wild debugging a lot and allows the receiver to do
more elaborate checks on the validity of the response.

MFC after: 2 weeks
Sponsored by: TCP/IP Optimization Fundraise 2005

Commit correct version of the change and note the name of the new
sysctl: net.inet.icmp.quotelen and defaults to 8 bytes.

Pointy hat to: andre

Add a sysctl to change to length of the quotation of the original
packet in an ICMP reply. The minimum of 8 bytes is internally
enforced. The maximum quotation is the remaining space in the
reply mbuf.

This option is added in response to the issues raised in I-D
draft-gont-icmp-payload-00.txt.

MFC after: 2 weeks
Spnsored by: TCP/IP Optimizations Fundraise 2005

Add an option to have ICMP replies to non-local packets generated with
the IP address the packet came through in. This is useful for routers
to show in traceroutes the actual path a packet has taken instead of
the possibly different return path.

The new sysctl is named net.inet.icmp.reply_from_interface and defaults
to off.

MFC after: 2 weeks

Add another step of 1280 (gif(4) tunnels) to ip_next_mtu().

Pass icmp_error() the MTU argument directly instead of
an interface pointer. This simplifies a couple of uses
and removes some XXX workarounds.

Move Path MTU discovery ICMP processing from icmp_input() to
tcp_ctlinput() and subject it to active tcpcb and sequence
number checking. Previously any ICMP unreachable/needfrag
message would cause an update to the TCP hostcache. Now only
ICMP PMTU messages belonging to an active TCP session with
the correct src/dst/port and sequence number will update the
hostcache and complete the path MTU discovery process.

Note that we don't entirely implement the recommended counter
measures of Section 7.2 of the paper. However we close down
the possible degradation vector from trivially easy to really
complex and resource intensive. In addition we have limited
the smallest acceptable MTU with net.inet.tcp.minmss sysctl
for some time already, further reducing the effect of any
degradation due to an attack.

Security: draft-gont-tcpm-icmp-attacks-03.txt Section 7.2
MFC after: 3 days

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

Remove the last two global variables that are used to store packet state while
it travels through the IP stack. This wasn't much of a problem because IP
source routing is disabled by default but when enabled together with SMP and
preemption it would have very likely cross-corrupted the IP options in transit.

The IP source route options of a packet are now stored in a mtag instead of the
global variable.

White space cleanup for netinet before branch:

- Trailing tab/space cleanup
- Remove spurious spaces between or before tabs

This change avoids touching files that Andre likely has in his working
set for PFIL hooks changes for IPFW/DUMMYNET.

Approved by: re (scottl)
Submitted by: Xin LI <delphij@frontfree.net>

Define semantic of M_SKIP_FIREWALL more precisely, i.e. also pass associated
icmp_error() packets. While here retire PACKET_TAG_PF_GENERATED (which
served the same purpose) and use M_SKIP_FIREWALL in pf as well. This should
speed up things a bit as we get rid of the tag allocations.

Discussed with: juli

Remove erroneous semicolons.

do not send icmp response if the original packet is encrypted.

Obtained from: KAME
MFC after: 1 week

o IFNAMSIZ does include the trailing \0.

Approved by: andre

o Document net.inet.icmp.reply_src.

Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson

Tweak existing header and other build infrastructure to be able to build
pf/pflog/pfsync as modules. Do not list them in NOTES or modules/Makefile
(i.e. do not connect it to any (automatic) builds - yet).

Approved by: bms(mentor)

Add sysctl net.inet.icmp.reply_src to specify the interface name
used for the ICMP reply source in reponse to packets which are not
directly addressed to us. By default continue with with normal
source selection.

Reviewed by: bms

More verbose description of the source ip address selection for ICMP replies.

Reviewed by: bms

Limiters and sanity checks for TCP MSS (maximum segement size)
resource exhaustion attacks.

For network link optimization TCP can adjust its MSS and thus
packet size according to the observed path MTU. This is done
dynamically based on feedback from the remote host and network
components along the packet path. This information can be
abused to pretend an extremely low path MTU.

The resource exhaustion works in two ways:

o during tcp connection setup the advertized local MSS is
exchanged between the endpoints. The remote endpoint can
set this arbitrarily low (except for a minimum MTU of 64
octets enforced in the BSD code). When the local host is
sending data it is forced to send many small IP packets
instead of a large one.

For example instead of the normal TCP payload size of 1448
it forces TCP payload size of 12 (MTU 64) and thus we have
a 120 times increase in workload and packets. On fast links
this quickly saturates the local CPU and may also hit pps
processing limites of network components along the path.

This type of attack is particularly effective for servers
where the attacker can download large files (WWW and FTP).

We mitigate it by enforcing a minimum MTU settable by sysctl
net.inet.tcp.minmss defaulting to 256 octets.

o the local host is reveiving data on a TCP connection from
the remote host. The local host has no control over the
packet size the remote host is sending. The remote host
may chose to do what is described in the first attack and
send the data in packets with an TCP payload of at least
one byte. For each packet the tcp_input() function will
be entered, the packet is processed and a sowakeup() is
signalled to the connected process.

For example an attack with 2 Mbit/s gives 4716 packets per
second and the same amount of sowakeup()s to the process
(and context switches).

This type of attack is particularly effective for servers
where the attacker can upload large amounts of data.
Normally this is the case with WWW server where large POSTs
can be made.

We mitigate this by calculating the average MSS payload per
second. If it goes below 'net.inet.tcp.minmss' and the pps
rate is above 'net.inet.tcp.minmssoverload' defaulting to
1000 this particular TCP connection is resetted and dropped.

MITRE CVE: CAN-2004-0002
Reviewed by: sam (mentor)
MFC after: 1 day

According to RFC1812 we have to ignore ICMP redirects when we
are acting as router (ipforwarding enabled).

This doesn't fix the problem that host routes from ICMP redirects
are never removed from the kernel routing table but removes the
problem for machines doing packet forwarding.

Reviewed by: sam (mentor)

Introduce tcp_hostcache and remove the tcp specific metrics from
the routing table. Move all usage and references in the tcp stack
from the routing table metrics to the tcp hostcache.

It caches measured parameters of past tcp sessions to provide better
initial start values for following connections from or to the same
source or destination. Depending on the network parameters to/from
the remote host this can lead to significant speedups for new tcp
connections after the first one because they inherit and shortcut
the learning curve.

tcp_hostcache is designed for multiple concurrent access in SMP
environments with high contention and is hash indexed by remote
ip address.

It removes significant locking requirements from the tcp stack with
regard to the routing table.

Reviewed by: sam (mentor), bms
Reviewed by: -net, -current, core@kame.net (IPv6 parts)
Approved by: re (scottl)

Remove RTF_PRCLONING from routing table and adjust users of it
accordingly. The define is left intact for ABI compatibility
with userland.

This is a pre-step for the introduction of tcp_hostcache. The
network stack remains fully useable with this change.

Reviewed by: sam (mentor), bms
Reviewed by: -net, -current, core@kame.net (IPv6 parts)
Approved by: re (scottl)

Remove the global one-level rtcache variable and associated
complex locking and rework ip_rtaddr() to do its own rtlookup.
Adopt all its callers to this and make ip_output() callable
with NULL rt pointer.

Reviewed by: sam (mentor)

Move global variables for icmp_input() to its stack. With SMP or
preemption two CPUs can be in the same function at the same time
and clobber each others variables. Remove register declaration
from local variables.

Reviewed by: sam (mentor)

Introduce the notion of "persistent mbuf tags"; these are tags that stay
with an mbuf until it is reclaimed. This is in contrast to tags that
vanish when an mbuf chain passes through an interface. Persistent tags
are used, for example, by MAC labels.

Add an m_tag_delete_nonpersistent function to strip non-persistent tags
from mbufs and use it to strip such tags from packets as they pass through
the loopback interface and when turned around by icmp. This fixes problems
with "tag leakage".

Pointed out by: Jonathan Stone
Reviewed by: Robert Watson

Locking for updates to routing table entries. Each rtentry gets a mutex
that covers updates to the contents. Note this is separate from holding
a reference and/or locking the routing table itself.

Other/related changes:

o rtredirect loses the final parameter by which an rtentry reference
may be returned; this was never used and added unwarranted complexity
for locking.
o minor style cleanups to routing code (e.g. ansi-fy function decls)
o remove the logic to bump the refcnt on the parent of cloned routes,
we assume the parent will remain as long as the clone; doing this avoids
a circularity in locking during delete
o convert some timeouts to MPSAFE callouts

Notes:

1. rt_mtx in struct rtentry is guarded by #ifdef _KERNEL as user-level
applications cannot/do-no know about mutex's. Doing this requires
that the mutex be the last element in the structure. A better solution
is to introduce an externalized version of struct rtentry but this is
a major task because of the intertwining of rtentry and other data
structures that are visible to user applications.
2. There are known LOR's that are expected to go away with forthcoming
work to eliminate many held references. If not these will be resolved
prior to release.
3. ATM changes are untested.

Sponsored by: FreeBSD Foundation
Obtained from: BSD/OS (partly)

Introduce two new MAC Framework and MAC policy entry points:

mac_reflect_mbuf_icmp()
mac_reflect_mbuf_tcp()

These entry points permit MAC policies to do "update in place"
changes to the labels on ICMP and TCP mbuf headers when an ICMP or
TCP response is generated to a packet outside of the context of
an existing socket. For example, in respond to a ping or a RST
packet to a SYN on a closed port.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Add a sysctl node allowing the specification of an address mask to use
when replying to ICMP Address Mask Request packets.

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.

correct style bogons

replace the special-purpose rate-limiting code with the general facility
just added; this tries to maintain the same behaviour vis a vis printing
the rate-limiting messages but need tweaking

Fix two instances of variant struct definitions in sys/netinet:

Remove the never completed _IP_VHL version, it has not caught on
anywhere and it would make us incompatible with other BSD netstacks
to retain this version.

Add a CTASSERT protecting sizeof(struct ip) == 20.

Don't let the size of struct ipq depend on the IPDIVERT option.

This is a functional no-op commit.

Approved by: re

Tie new "Fast IPsec" code into the build. This involves the usual
configuration stuff as well as conditional code in the IPv4 and IPv6
areas. Everything is conditional on FAST_IPSEC which is mutually
exclusive with IPSEC (KAME IPsec implmentation).

As noted previously, don't use FAST_IPSEC with INET6 at the moment.

Reviewed by: KAME, rwatson
Approved by: silence
Supported by: Vernier Networks

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

Introduce support for Mandatory Access Control and extensible
kernel access control.

Add support for labeling most out-going ICMP messages using an
appropriate MAC entry point. Currently, we do not explicitly
label packet reflect (timestamp, echo request) ICMP events,
implicitly using the originating packet label since the mbuf is
reused. This will be made explicit at some point.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs

Prevent icmp_reflect() from calling ip_output() with a NULL route
pointer which will then result in the allocated route's reference
count never being decremented. Just flood ping the localhost and
watch refcnt of the 127.0.0.1 route with netstat(1).

Submitted by: jayanth

Back out ip_output.c,v 1.143 and ip_mroute.c,v 1.69 that allowed
ip_output() to be called with a NULL route pointer. The previous
paragraph shows why this was a bad idea in the first place.

MFC after: 0 days

Remove __P.

o Move NTOHL() and associated macros into <sys/param.h>. These are
deprecated in favor of the POSIX-defined lowercase variants.
o Change all occurrences of NTOHL() and associated marcros in the
source tree to use the lowercase function variants.
o Add missing license bits to sparc64's <machine/endian.h>.
Approved by: jake
o Clean up <machine/endian.h> files.
o Remove unused __uint16_swap_uint32() from i386's <machine/endian.h>.
o Remove prototypes for non-existent bswapXX() functions.
o Include <machine/endian.h> in <arpa/inet.h> to define the
POSIX-required ntohl() family of functions.
o Do similar things to expose the ntohl() family in libstand, <netinet/in.h>,
and <sys/param.h>.
o Prepend underscores to the ntohl() family to help deal with
complexities associated with having MD (asm and inline) versions, and
having to prevent exposure of these functions in other headers that
happen to make use of endian-specific defines.
o Create weak aliases to the canonical function name to help deal with
third-party software forgetting to include an appropriate header.
o Remove some now unneeded pollution from <sys/types.h>.
o Add missing <arpa/inet.h> includes in userland.

Tested on: alpha, i386
Reviewed by: bde, jake, tmm

Fix a panic condition in icmp_reflect() introduced in rev. 1.61.
(We should be able to handle locally originated IP packets, and
these do not have m_pkthdr.rcvif set.)

PR: kern/32806, kern/33766
Reviewed by: luigi
Fix tested by: Maxim Konovalov <maxim@macomnet.ru>,
Erwin Lansing <erwin@lansing.dk>

whitespace fixes.

- Make ip_rtaddr() global, and use it to look up the correct source
address in icmp_reflect().
- Two new "struct icmpstat" members: icps_badaddr and icps_noroute.

PR: kern/31575
Obtained from: BSD/OS
MFC after: 1 week

In icmp_reflect(): If the packet was not addressed to us and was
received on an interface without an IP address, try to find a
non-loopback AF_INET address to use. If that fails, drop it.
Previously, we used the address at the top of the in_ifaddrhead list,
which didn't make much sense, and would cause a panic if there were no
AF_INET addresses configured on the system.

PR: 29337, 30524
Reviewed by: ru, jlemon
Obtained from: NetBSD

Relocate the KASSERT for a null recvif to a location where it will
actually do some good.

Pointed out by: ru

Add a hash table that contains the list of internet addresses, and use
this in place of the in_ifaddr list when appropriate. This improves
performance on hosts which have a large number of IP aliases.

Make faith loadable, unloadable, and clonable.

Patches from Keiichi SHIMA <keiichi@iij.ad.jp>
to make ip use the standard protosw structure again.

Obtained from: Well, KAME I guess.

Add netstat(1) knob to reset net.inet.{ip|icmp|tcp|udp|igmp}.stats.
For example, ``netstat -s -p ip -z'' will show and reset IP stats.

PR: bin/17338

Sync with recent KAME.
This work was based on kame-20010528-freebsd43-snap.tgz and some
critical problem after the snap was out were fixed.
There are many many changes since last KAME merge.

TODO:
- The definitions of SADB_* in sys/net/pfkeyv2.h are still different
from RFC2407/IANA assignment because of binary compatibility
issue. It should be fixed under 5-CURRENT.
- ip6po_m member of struct ip6_pktopts is no longer used. But, it
is still there because of binary compatibility issue. It should
be removed under 5-CURRENT.

Reviewed by: itojun
Obtained from: KAME
MFC after: 3 weeks

MFC candidate.

Change code from PRC_UNREACH_ADMIN_PROHIB to PRC_UNREACH_PORT for
ICMP_UNREACH_PROTOCOL and ICMP_UNREACH_PORT

And let TCP treat PRC_UNREACH_PORT like PRC_UNREACH_ADMIN_PROHIB

This should fix the case where port unreachables for udp returned
ENETRESET instead of ECONNREFUSED

Problem found by: Bill Fenner <fenner@research.att.com>
Reviewed by: jlemon

Make it possible to use IP_TTL and IP_TOS setsockopt(2) options
on certain types of SOCK_RAW sockets. Also, use the ip.ttl MIB
variable instead of MAXTTL constant as the default time-to-live
value for outgoing IP packets all over the place, as we already
do this for TCP and UDP.

Reviewed by: wollman

It was possible for ip_forward() to supply to icmp_error()
an IP header with ip_len in network byte order. For certain
values of ip_len, this could cause icmp_error() to write
beyond the end of an mbuf, causing mbuf free-list corruption.
This problem was observed during generation of ICMP redirects.

We now make quite sure that the copy of the IP header kept
for icmp_error() is stored in a non-shared mbuf header so
that it will not be modified by ip_output().

Also:
- Calculate the correct number of bytes that need to be
retained for icmp_error(), instead of assuming that 64
is enough (it's not).
- In icmp_error(), use m_copydata instead of bcopy() to
copy from the supplied mbuf chain, in case the first 8
bytes of IP payload are not stored directly after the IP
header.
- Sanity-check ip_len in icmp_error(), and panic if it is
less than sizeof(struct ip). Incoming packets with bad
ip_len values are discarded in ip_input(), so this should
only be triggered by bugs in the code, not by bad packets.

This patch results from code and suggestions from Ruslan, Bosko,
Jonathan Lemon and Matt Dillon, with important testing by Mike
Tancsa, who could reproduce this problem at will.

Reported by: Mike Tancsa <mike@sentex.net>
Reviewed by: ru, bmilekic, jlemon, dillon

Allow ICMP unreachables which map into PRC_UNREACH_ADMIN_PROHIB to
reset TCP connections which are in the SYN_SENT state, if the sequence
number in the echoed ICMP reply is correct. This behavior can be
controlled by the sysctl net.inet.tcp.icmp_may_rst.

Currently, only subtypes 2,3,10,11,12 are treated as such
(port, protocol and administrative unreachables).

Assocaiate an error code with these resets which is reported to the
user application: ENETRESET.

Disallow resetting TCP sessions which are not in a SYN_SENT state.

Reviewed by: jesper, -net

Remove unneeded loop increment in src/sys/netinet/in_pcb.c:in_pcbnotify

Add new PRC_UNREACH_ADMIN_PROHIB in sys/sys/protosw.h

Remove condition on TCP in src/sys/netinet/ip_icmp.c:icmp_input

In src/sys/netinet/ip_icmp.c:icmp_input set code = PRC_UNREACH_ADMIN_PROHIB
or PRC_UNREACH_HOST for all unreachables except ICMP_UNREACH_NEEDFRAG

Rename sysctl icmp_admin_prohib_like_rst to icmp_unreach_like_rst
to reflect the fact that we also react on ICMP unreachables that
are not administrative prohibited. Also update the comments to
reflect this.

In sys/netinet/tcp_subr.c:tcp_ctlinput add code to treat
PRC_UNREACH_ADMIN_PROHIB and PRC_UNREACH_HOST different.

PR: 23986
Submitted by: Jesper Skriver <jesper@skriver.dk>

Clean up RST ratelimiting. Previously, ratelimiting occured before tests
were performed to determine if the received packet should be reset. This
created erroneous ratelimiting and false alarms in some cases. The code
has now been reorganized so that the checks for validity come before
the call to badport_bandlim. Additionally, a few changes in the symbolic
names of the bandlim types have been made, as well as a clarification of
exactly which type each RST case falls under.

Submitted by: Mike Silbersack <silby@silby.com>

Mechanical change to use <sys/queue.h> macro API instead of
fondling implementation details.

Created with: sed(1)
Reviewed by: md5(1)

Use getmicrotime() instead of microtime() when timestamping ICMP packets,
the former is quicker and accurate enough for use here.

Submitted by: Jason Slagle <raistlin@toledolink.com> (on IRC)
Reviewed by: phk

We currently does not react to ICMP administratively prohibited
messages send by routers when they deny our traffic, this causes
a timeout when trying to connect to TCP ports/services on a remote
host, which is blocked by routers or firewalls.

rfc1122 (Requirements for Internet Hosts) section 3.2.2.1 actually
requi re that we treat such a message for a TCP session, that we
treat it like if we had recieved a RST.

quote begin.

A Destination Unreachable message that is received MUST be
reported to the transport layer. The transport layer SHOULD
use the information appropriately; for example, see Sections
4.1.3.3, 4.2.3.9, and 4.2.4 below. A transport protocol
that has its own mechanism for notifying the sender that a
port is unreachable (e.g., TCP, which sends RST segments)
MUST nevertheless accept an ICMP Port Unreachable for the
same purpose.

quote end.

I've written a small extension that implement this, it also create
a sysctl "net.inet.tcp.icmp_admin_prohib_like_rst" to control if
this new behaviour is activated.

When it's activated (set to 1) we'll treat a ICMP administratively
prohibited message (icmp type 3 code 9, 10 and 13) for a TCP
sessions, as if we recived a TCP RST, but only if the TCP session
is in SYN_SENT state.

The reason for only reacting when in SYN_SENT state, is that this
will solve the problem, and at the same time minimize the risk of
this being abused.

I suggest that we enable this new behaviour by default, but it
would be a change of current behaviour, so if people prefer to
leave it disabled by default, at least for now, this would be ok
for me, the attached diff actually have the sysctl set to 0 by
default.

PR: 23086
Submitted by: Jesper Skriver <jesper@skriver.dk>

Change the following:

1. ICMP ECHO and TSTAMP replies are now rate limited.
2. RSTs generated due to packets sent to open and unopen ports
are now limited by seperate counters.
3. Each rate limiting queue now has its own description, as
follows:

Limiting icmp unreach response from 439 to 200 packets per second
Limiting closed port RST response from 283 to 200 packets per second
Limiting open port RST response from 18724 to 200 packets per second
Limiting icmp ping response from 211 to 200 packets per second
Limiting icmp tstamp response from 394 to 200 packets per second

Submitted by: Mike Silbersack <silby@silby.com>

Fixed the bug I have introduced in icmp_error() in revision 1.44.
The amount of data we copy from the original IP datagram into the
ICMP message was computed incorrectly for IP packets with payload
less than 8 bytes.

Follow BSD/OS and NetBSD, keep the ip_id field in network order all the time.

Requested by: wollman

Fixed broken ICMP error generation, unified conversion of IP header
fields between host and network byte order. The details:

o icmp_error() now does not add IP header length. This fixes the problem
when icmp_error() is called from ip_forward(). In this case the ip_len
of the original IP datagram returned with ICMP error was wrong.

o icmp_error() expects all three fields, ip_len, ip_id and ip_off in host
byte order, so DTRT and convert these fields back to network byte order
before sending a message. This fixes the problem described in PR 16240
and PR 20877 (ip_id field was returned in host byte order).

o ip_ttl decrement operation in ip_forward() was moved down to make sure
that it does not corrupt the copy of original IP datagram passed later
to icmp_error().

o A copy of original IP datagram in ip_forward() was made a read-write,
independent copy. This fixes the problem I first reported to Garrett
Wollman and Bill Fenner and later put in audit trail of PR 16240:
ip_output() (not always) converts fields of original datagram to network
byte order, but because copy (mcopy) and its original (m) most likely
share the same mbuf cluster, ip_output()'s manipulations on original
also corrupted the copy.

o ip_output() now expects all three fields, ip_len, ip_off and (what is
significant) ip_id in host byte order. It was a headache for years that
ip_id was handled differently. The only compatibility issue here is the
raw IP socket interface with IP_HDRINCL socket option set and a non-zero
ip_id field, but ip.4 manual page was unclear on whether in this case
ip_id field should be in host or network byte order.

Add boundary checks against IP options.

Obtained from: OpenBSD

sysctl'ize ICMP_BANDLIM and ICMP_BANDLIM_SUPPRESS_OUTPUT.

Suggested by: des/nbm

Add option ICMP_BANDLIM_SUPPRESS_OUTPUT to the mix. With this option,
badport_bandlim() will not muck up your console with printf() messages.

Add #include <machine/in_cksum.h>, in order to pick up the checksum
inline functions and prototypes.

Mitigate the stream.c attacks

o Drop all broadcast and multicast source addresses in tcp_input.
o Enable ICMP_BANDLIM in GENERIC.
o Change default to 200/s from 100/s. This will still stop the attack, but
is conservative enough to do this close to code freeze.

This is not the optimal patch for the problem, but is likely the least
intrusive patch that can be made for this.

Obtained from: Don Lewis and Matt Dillon.
Reviewed by: freebsd-security

IPSEC support in the kernel.
pr_input() routines prototype is also changed to support IPSEC and IPV6
chained protocol headers.

Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project

Reorder.

$Id$ -> $FreeBSD$

Add net.inet.icmp.log_redirect and net.inet.icmp.drop_redirect, for
respectively logging and dropping ICMP REDIRECT packets.

Note that there is no rate limiting on the log messages, so log_redirect
should be used with caution (preferrably only for debugging purposes).

When an incoming packet is reflected back as an ICMP reply, make sure we
zero "m->m_pkthdr.rcvif", otherwise ipfw may wrongly match the outgoing packet.
PR: kern/9723
Submitted by: David Malone <dwmalone@maths.tcd.ie>

Cleanup icmp_var.h, make icmp bandlim sysctl permanent but if ICMP_BANDLIM
option not defined the sysctl int value is set to -1 and read-only.

#ifdef KERNEL's added appropriately to wall off visibility of kernel
routines from user code.

Reviewed by: freebsd-current

Add ICMP_BANDLIM option and 'net.inet.icmp.icmplim' sysctl. If option
is specified in kernel config, icmplim defaults to 100 pps. Setting it
to 0 will disable the feature. This feature limits ICMP error responses
for packets sent to bad tcp or udp ports, which does a lot to help the
machine handle network D.O.S. attacks.

The kernel will report packet rates that exceed the limit at a rate of
one kernel printf per second. There is one issue in regards to the
'tail end' of an attack... the kernel will not output the last report
until some unrelated and valid icmp error packet is return at some
point after the attack is over. This is a minor reporting issue only.

Turn off replies to ICMP echo requests for broadcast and multicast
addresses by default.

Add a knob "icmp_bmcastecho" to "rc.network" to allow this
behaviour to be controlled from "rc.conf".

Document the controlling sysctl variable "net.inet.icmp.bmcastecho"
in sysctl(3).

Reviewed by: dg, jkh
Reminded on -hackers by: Steinar Haug <sthaug@nethelp.no>

Fixed logic in the test to drop ICMP echo and timestamp packets when
net.inet.ip.icmp.bmcastecho = 0 by removing the extra check for the
address being a multicast address. The test now relies on the link
layer flags that indicate it was received via multicast. The previous
logic was broken and replied to ICMP echo/timestamp broadcasts even
when the sysctl option disallowed them.
Reviewed by: wollman

ICMP Timestamp Request messages could have harbored the same sort of
problem as Echo Requests when broad/multicast. When multicast echo responses
are disabled, also do the same for timestamp responses.

Configurably don't reply to broadcast or multicast echos. There are still
potential problems with other automatic-reply ICMPs, but some of them may
depend on broadcast/multicast to operate. (This code can simply be
moved to the `reflect' label to generalize it.)

Removed unused #includes.

submitted by: archie@whistle.com

Don't search for interface addresses matching interface "NULL"
it's likely to cause a page fault..
this can be triggered by the ipfw code rejecting a locally generated
packet (e.g. you decide to make some network unreachable by local users)

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Convert the interface address and IP interface address structures
to TAILQs. Fix places which referenced these for no good reason
that I can see (the references remain, but were fixed to compile
again; they are still questionable).

Handle ICMP codes defined in RFC1812 more appropriately

Eliminate some more references to separate ip_v and ip_hl fields.

Always pass a route structure when calling ip_output().

Fix two cases where ia->ia_ifp could be NULL.

Make rip_input() take the header length
Move ipip_input() and rsvp_input() prototypes to ip_var.h
Remove unused prototype for rip_ip_input() from ip_var.h
Remove unused variable *opts from rip_output()

Uniformized pr_ctlinput protosw functions. The third arg is now `void
*' instead of caddr_t and it isn't optional (it never was). Most of the
netipx (and netns) pr_ctlinput functions abuse the second arg instead of
using the third arg but fixing this is beyond the scope of this round
of changes.

Another mega commit to staticize things.

Added a conditionalized printf for debugging MTU discovery.

Removed unnecessary #includes of vm stuff. Most of them were once
prerequisites for <sys/sysctl.h>.

subr_prof.c:
Also replaced #include of <sys/user.h> by #include of <sys/resourcevar.h>.

Path MTU Discovery is now standard.

Fixed the type of a function pointer.

New style sysctl & staticize alot of stuff.

Initial back-end support for IP MTU discovery, gated on MTUDISC. The support
for TCP has yet to be written.

Fix long-standing bug in ICMPPRINTFS code where NTOHL was used instead
of ntohl for printing IP addresses, by instead substituting inet_ntoa()
to produce human-readable output.

Obtained from: 4.4-Lite-2

ICMP messages received from broken hosts which reply to multicast packets
were mistakenly delivered, rather than getting thrown out, which caused
substantial lossage.

Submitted by: Bill Fenner <fenner@parc.xerox.com>

Remove trailing whitespace.

Add and move declarations to fix all of the warnings from `gcc -Wimplicit'
(except in netccitt, netiso and netns) and most of the warnings from
`gcc -Wnested-externs'. Fix all the bugs found. There were no serious
ones.

Add lots of useful MIB variables and a few not-so-useful ones for
completeness.

Cosmetics: silences gcc -Wall.

GCC cleanup.
Reviewed by:
Submitted by:
Obtained from:

Added $Id$

This commit was generated by cvs2svn to compensate for changes in r1541,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite Kernel Sources