MFC r338138:

Enabling the IPPROTO_IPV6 level socket option IPV6_USE_MIN_MTU on a TCP
socket resulted in sending fragmented IPV6 packets.

This is fixes by reducing the MSS to the appropriate value. In addtion,
if the socket option is set before the handshake happens, announce this
MSS to the peer. This is not stricly required, but done since TCP
is conservative.

PR: 173444
Reviewed by: bz@, rrs@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D16796

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)

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

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

Add spares to struct ifnet and socket for packet pacing and/or general
use. Update comments regarding the spare fields in struct inpcb.

Bump __FreeBSD_version for the changes to the size of the structures.

Reviewed by: gnn@
Approved by: re@ (gjb@)
Sponsored by: Chelsio Communications

sys/net*: minor spelling fixes.

No functional change.

FreeBSD previously provided route caching for TCP (and UDP). Re-add
route caching for TCP, with some improvements. In particular, invalidate
the route cache if a new route is added, which might be a better match.
The cache is automatically invalidated if the old route is deleted.

Submitted by: Mike Karels
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D4306

Use Jenkins hash for TCP syncache.

o Unlike xor, in Jenkins hash every bit of input affects virtually
every bit of output, thus salting the hash actually works. With
xor salting only provides a false sense of security, since if
hash(x) collides with hash(y), then of course, hash(x) ^ salt
would also collide with hash(y) ^ salt. [1]
o Jenkins provides much better distribution than xor, very close to
ideal.

TCP connection setup/teardown benchmark has shown a 10% increase
with default hash size, and with bigger hashes that still provide
possibility for collisions. With enormous hash size, when dataset is
by an order of magnitude smaller than hash size, the benchmark has
shown 4% decrease in performance decrease, which is expected and
acceptable.

Noticed by: Jeffrey Knockel <jeffk cs.unm.edu> [1]
Benchmarks by: jch
Reviewed by: jch, pkelsey, delphij
Security: strengthens protection against hash collision DoS
Sponsored by: Nginx, Inc.

Fix a kernel assertion issue introduced with r286227:
Avoid too strict INP_INFO_RLOCK_ASSERT checks due to
tcp_notify() being called from in6_pcbnotify().

Reported by: Larry Rosenman <ler@lerctr.org>
Submitted by: markj, jch

Decompose TCP INP_INFO lock to increase short-lived TCP connections scalability:

- The existing TCP INP_INFO lock continues to protect the global inpcb list
stability during full list traversal (e.g. tcp_pcblist()).

- A new INP_LIST lock protects inpcb list actual modifications (inp allocation
and free) and inpcb global counters.

It allows to use TCP INP_INFO_RLOCK lock in critical paths (e.g. tcp_input())
and INP_INFO_WLOCK only in occasional operations that walk all connections.

PR: 183659
Differential Revision: https://reviews.freebsd.org/D2599
Reviewed by: jhb, adrian
Tested by: adrian, nitroboost-gmail.com
Sponsored by: Verisign, Inc.

Start process of removing the use of the deprecated "M_FLOWID" flag
from the FreeBSD network code. The flag is still kept around in the
"sys/mbuf.h" header file, but does no longer have any users. Instead
the "m_pkthdr.rsstype" field in the mbuf structure is now used to
decide the meaning of the "m_pkthdr.flowid" field. To modify the
"m_pkthdr.rsstype" field please use the existing "M_HASHTYPE_XXX"
macros as defined in the "sys/mbuf.h" header file.

This patch introduces new behaviour in the transmit direction.
Previously network drivers checked if "M_FLOWID" was set in "m_flags"
before using the "m_pkthdr.flowid" field. This check has now now been
replaced by checking if "M_HASHTYPE_GET(m)" is different from
"M_HASHTYPE_NONE". In the future more hashtypes will be added, for
example hashtypes for hardware dedicated flows.

"M_HASHTYPE_OPAQUE" indicates that the "m_pkthdr.flowid" value is
valid and has no particular type. This change removes the need for an
"if" statement in TCP transmit code checking for the presence of a
valid flowid value. The "if" statement mentioned above is now a direct
variable assignment which is then later checked by the respective
network drivers like before.

Additional notes:
- The SCTP code changes will be committed as a separate patch.
- Removal of the "M_FLOWID" flag will also be done separately.
- The FreeBSD version has been bumped.

MFC after: 1 month
Sponsored by: Mellanox Technologies

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@

Add scope zone id to the in_endpoints and hc_metrics structures.

A non-global IPv6 address can be used in more than one zone of the same
scope. This zone index is used to identify to which zone a non-global
address belongs.

Also we can have many foreign hosts with equal non-global addresses,
but from different zones. So, they can have different metrics in the
host cache.

Obtained from: Yandex LLC
Sponsored by: Yandex LLC

Introduce INP6_PCBHASHKEY macro. Replace usage of hardcoded part of
IPv6 address as hash key in all places.

Obtained from: Yandex LLC

Add support for receiving and setting flowtype, flowid and RSS bucket
information as part of recvmsg().

This is primarily used for debugging/verification of the various
processing paths in the IP, PCB and driver layers.

Unfortunately the current implementation of the control message path
results in a ~10% or so drop in UDP frame throughput when it's used.

Differential Revision: https://reviews.freebsd.org/D527
Reviewed by: grehan

Expose in_pcbbind_check_bindmulti() so the upcoming IPv6 RSS changes
can be made to use it.

Implement the first stage of multi-bind listen sockets and RSS socket
awareness.

* Introduce IP_BINDMULTI - indicating that it's okay to bind multiple
sockets on the same bind details.

Although the PCB code has been taught about this (see below) this patch
doesn't introduce the rest of the PCB changes necessary to distribute
lookups among multiple PCB entries in the global wildcard table.

* Introduce IP_RSS_LISTEN_BUCKET - placing an listen socket into the
given RSS bucket (and thus a single PCBGROUP hash.)

* Modify the PCB add path to be aware of IP_BINDMULTI:
+ Only allow further PCB entries to be added if the owner credentials
and IP_BINDMULTI has been specified. Ie, only allow further
IP_BINDMULTI sockets to appear if the first bind() was IP_BINDMULTI.

* Teach the PCBGROUP code about IP_RSS_LISTE_BUCKET marked PCB entries.
Instead of using the wildcard logic and hashing, these sockets are
simply placed into the PCBGROUP and _not_ in the wildcard hash.

* When doing a PCBGROUP lookup, also do a wildcard match as well.
This allows for an RSS bucket PCB entry to appear in a PCBGROUP
rather than having to exist in the wildcard list.

Tested:

* TCP IPv4 server testing with igb(4)
* TCP IPv4 server testing with ix(4)

TODO:

* The pcbgroup lookup code duplicated the wildcard and wildcard-PCB
logic. This could be refactored into a single function.

* This doesn't yet work for IPv6 (The PCBGROUP code in netinet6/ doesn't
yet know about this); nor does it yet fully work for UDP.

Add the flowtype to the inpcb.

The flowid isn't enough to use as part of any RSS related CPU affinity
lookups - the RSS code would like to know what kind of hash it is.

Fix jailed raw sockets not setting the correct source address by
calling in_pcbladdr instead of prison_get_ip4

MFC after: 1 month

In r227207, to fix the issue with possible NULL inp_socket pointer
dereferencing, when checking for SO_REUSEPORT option (and SO_REUSEADDR
for multicast), INP_REUSEPORT flag was introduced to cache the socket
option. It was decided then that one flag would be enough to cache
both SO_REUSEPORT and SO_REUSEADDR: when processing SO_REUSEADDR
setsockopt(2), it was checked if it was called for a multicast address
and INP_REUSEPORT was set accordingly.

Unfortunately that approach does not work when setsockopt(2) is called
before binding to a multicast address: the multicast check fails and
INP_REUSEPORT is not set.

Fix this by adding INP_REUSEADDR flag to unconditionally cache
SO_REUSEADDR.

PR: 179901
Submitted by: Michael Gmelin freebsd grem.de (initial version)
Reviewed by: rwatson
MFC after: 1 week

Back out r249318, r249320 and r249327 due to a heisenbug most
likely related to a race condition in the ipi_hash_lock with
the exact cause currently unknown but under investigation.

Change certain heavily used network related mutexes and rwlocks to
reside on their own cache line to prevent false sharing with other
nearby structures, especially for those in the .bss segment.

NB: Those mutexes and rwlocks with variables next to them that get
changed on every invocation do not benefit from their own cache line.
Actually it may be net negative because two cache misses would be
incurred in those cases.

There is a complex race in in_pcblookup_hash() and in_pcblookup_group().
Both functions need to obtain lock on the found PCB, and they can't do
classic inter-lock with the PCB hash lock, due to lock order reversal.
To keep the PCB stable, these functions put a reference on it and after PCB
lock is acquired drop it. If the reference was the last one, this means
we've raced with in_pcbfree() and the PCB is no longer valid.

This approach works okay only if we are acquiring writer-lock on the PCB.
In case of reader-lock, the following scenario can happen:

- 2 threads locate pcb, and do in_pcbref() on it.
- These 2 threads drop the inp hash lock.
- Another thread comes to delete pcb via in_pcbfree(), it obtains hash lock,
does in_pcbremlists(), drops hash lock, and runs in_pcbrele_wlocked(), which
doesn't free the pcb due to two references on it. Then it unlocks the pcb.
- 2 aforementioned threads acquire reader lock on the pcb and run
in_pcbrele_rlocked(). One gets 1 from in_pcbrele_rlocked() and continues,
second gets 0 and considers pcb freed, returns.
- The thread that got 1 continutes working with detached pcb, which later
leads to panic in the underlying protocol level.

To plumb that problem an additional INPCB flag introduced - INP_FREED. We
check for that flag in the in_pcbrele_rlocked() and if it is set, we pretend
that that was the last reference.

Discussed with: rwatson, jhb
Reported by: Vladimir Medvedkin <medved rambler-co.ru>

Add a IP_RECVTOS socket option to receive for received UDP/IPv4
packets a cmsg of type IP_RECVTOS which contains the TOS byte.
Much like IP_RECVTTL does for TTL. This allows to implement a
protocol on top of UDP and implementing ECN.

MFC after: 3 days

Hide a few declarations from userland (including `struct inpcbgroup'). This
removes the dependency on <machine/param.h> which was introduced with SVN
rev 222748 (due to CACHE_LINE_SIZE).

Reviewed by: bde
MFC after: 10 days

Cache SO_REUSEPORT socket option in inpcb-layer in order to avoid
inp_socket->so_options dereference when we may not acquire the lock on
the inpcb.

This fixes the crash due to NULL pointer dereference in
in_pcbbind_setup() when inp_socket->so_options in a pcb returned by
in_pcblookup_local() was checked.

Reported by: dave jones <s.dave.jones@gmail.com>, Arnaud Lacombe <lacombar@gmail.com>
Suggested by: rwatson
Glanced by: rwatson
Tested by: dave jones <s.dave.jones@gmail.com>

Add spares to the network stack for FreeBSD-9:
- TCP keep* timers
- TCP UTO (adjust from what was there already)
- netmap
- route caching
- user cookie (temporary to allow for the real fix)

Slightly re-shuffle struct ifnet moving fields out of the middle
of spares and to better align.

Discussed with: rwatson (slightly earlier version)

Unbreak kernels with non-default PCBGROUP included but no WITNESS.
Rather than including lock.h in in_pcbgroup.c in right order, fix it
for all consumers of in_pcb.h by further header file pollution under
#ifdef KERNEL.

Reported by: Pan Tsu (inyaoo gmail.com)

Implement a CPU-affine TCP and UDP connection lookup data structure,
struct inpcbgroup. pcbgroups, or "connection groups", supplement the
existing inpcbinfo connection hash table, which when pcbgroups are
enabled, might now be thought of more usefully as a per-protocol
4-tuple reservation table.

Connections are assigned to connection groups base on a hash of their
4-tuple; wildcard sockets require special handling, and are members
of all connection groups. During a connection lookup, a
per-connection group lock is employed rather than the global pcbinfo
lock. By aligning connection groups with input path processing,
connection groups take on an effective CPU affinity, especially when
aligned with RSS work placement (see a forthcoming commit for
details). This eliminates cache line migration associated with
global, protocol-layer data structures in steady state TCP and UDP
processing (with the exception of protocol-layer statistics; further
commit to follow).

Elements of this approach were inspired by Willman, Rixner, and Cox's
2006 USENIX paper, "An Evaluation of Network Stack Parallelization
Strategies in Modern Operating Systems". However, there are also
significant differences: we maintain the inpcb lock, rather than using
the connection group lock for per-connection state.

Likewise, the focus of this implementation is alignment with NIC
packet distribution strategies such as RSS, rather than pure software
strategies. Despite that focus, software distribution is supported
through the parallel netisr implementation, and works well in
configurations where the number of hardware threads is greater than
the number of NIC input queues, such as in the RMI XLR threaded MIPS
architecture.

Another important difference is the continued maintenance of existing
hash tables as "reservation tables" -- these are useful both to
distinguish the resource allocation aspect of protocol name management
and the more common-case lookup aspect. In configurations where
connection tables are aligned with hardware hashes, it is desirable to
use the traditional lookup tables for loopback or encapsulated traffic
rather than take the expense of hardware hashes that are hard to
implement efficiently in software (such as RSS Toeplitz).

Connection group support is enabled by compiling "options PCBGROUP"
into your kernel configuration; for the time being, this is an
experimental feature, and hence is not enabled by default.

Subject to the limited MFCability of change dependencies in inpcb,
and its change to the inpcbinfo init function signature, this change
in principle could be merged to FreeBSD 8.x.

Reviewed by: bz
Sponsored by: Juniper Networks, Inc.

Add _mbuf() variants of various inpcb-related interfaces, including lookup,
hash install, etc. For now, these are arguments are unused, but as we add
RSS support, we will want to use hashes extracted from mbufs, rather than
manually calculated hashes of header fields, due to the expensive of the
software version of Toeplitz (and similar hashes).

Add notes that it would be nice to be able to pass mbufs into lookup
routines in pf(4), optimising firewall lookup in the same way, but the
code structure there doesn't facilitate that currently.

(In principle there is no reason this couldn't be MFCed -- the change
extends rather than modifies the KBI. However, it won't be useful without
other previous possibly less MFCable changes.)

Reviewed by: bz
Sponsored by: Juniper Networks, Inc.

Decompose the current single inpcbinfo lock into two locks:

- The existing ipi_lock continues to protect the global inpcb list and
inpcb counter. This lock is now relegated to a small number of
allocation and free operations, and occasional operations that walk
all connections (including, awkwardly, certain UDP multicast receive
operations -- something to revisit).

- A new ipi_hash_lock protects the two inpcbinfo hash tables for
looking up connections and bound sockets, manipulated using new
INP_HASH_*() macros. This lock, combined with inpcb locks, protects
the 4-tuple address space.

Unlike the current ipi_lock, ipi_hash_lock follows the individual inpcb
connection locks, so may be acquired while manipulating a connection on
which a lock is already held, avoiding the need to acquire the inpcbinfo
lock preemptively when a binding change might later be required. As a
result, however, lookup operations necessarily go through a reference
acquire while holding the lookup lock, later acquiring an inpcb lock --
if required.

A new function in_pcblookup() looks up connections, and accepts flags
indicating how to return the inpcb. Due to lock order changes, callers
no longer need acquire locks before performing a lookup: the lookup
routine will acquire the ipi_hash_lock as needed. In the future, it will
also be able to use alternative lookup and locking strategies
transparently to callers, such as pcbgroup lookup. New lookup flags are,
supplementing the existing INPLOOKUP_WILDCARD flag:

INPLOOKUP_RLOCKPCB - Acquire a read lock on the returned inpcb
INPLOOKUP_WLOCKPCB - Acquire a write lock on the returned inpcb

Callers must pass exactly one of these flags (for the time being).

Some notes:

- All protocols are updated to work within the new regime; especially,
TCP, UDPv4, and UDPv6. pcbinfo ipi_lock acquisitions are largely
eliminated, and global hash lock hold times are dramatically reduced
compared to previous locking.
- The TCP syncache still relies on the pcbinfo lock, something that we
may want to revisit.
- Support for reverting to the FreeBSD 7.x locking strategy in TCP input
is no longer available -- hash lookup locks are now held only very
briefly during inpcb lookup, rather than for potentially extended
periods. However, the pcbinfo ipi_lock will still be acquired if a
connection state might change such that a connection is added or
removed.
- Raw IP sockets continue to use the pcbinfo ipi_lock for protection,
due to maintaining their own hash tables.
- The interface in6_pcblookup_hash_locked() is maintained, which allows
callers to acquire hash locks and perform one or more lookups atomically
with 4-tuple allocation: this is required only for TCPv6, as there is no
in6_pcbconnect_setup(), which there should be.
- UDPv6 locking remains significantly more conservative than UDPv4
locking, which relates to source address selection. This needs
attention, as it likely significantly reduces parallelism in this code
for multithreaded socket use (such as in BIND).
- In the UDPv4 and UDPv6 multicast cases, we need to revisit locking
somewhat, as they relied on ipi_lock to stablise 4-tuple matches, which
is no longer sufficient. A second check once the inpcb lock is held
should do the trick, keeping the general case from requiring the inpcb
lock for every inpcb visited.
- This work reminds us that we need to revisit locking of the v4/v6 flags,
which may be accessed lock-free both before and after this change.
- Right now, a single lock name is used for the pcbhash lock -- this is
undesirable, and probably another argument is required to take care of
this (or a char array name field in the pcbinfo?).

This is not an MFC candidate for 8.x due to its impact on lookup and
locking semantics. It's possible some of these issues could be worked
around with compatibility wrappers, if necessary.

Reviewed by: bz
Sponsored by: Juniper Networks, Inc.

Continue to refine inpcb reference counting and locking, in preparation for
reworking of inpcbinfo locking:

(1) Convert inpcb reference counting from manually manipulated integers to
the refcount(9) KPI. This allows the refcount to be managed atomically
with an inpcb read lock rather than write lock, or even with no inpcb
lock at all. As a result, in_pcbref() also no longer requires an inpcb
lock, so can be performed solely using the lock used to look up an
inpcb.

(2) Shift more inpcb freeing activity from the in_pcbrele() context (via
in_pcbfree_internal) to the explicit in_pcbfree() context. This means
that the inpcb refcount is increasingly used only to maintain memory
stability, not actually defer the clean up of inpcb protocol parts.
This is desirable as many of those protocol parts required the pcbinfo
lock, which we'd like not to acquire in in_pcbrele() contexts. Document
this in comments better.

(3) Introduce new read-locked and write-locked in_pcbrele() variations,
in_pcbrele_rlocked() and in_pcbrele_wlocked(), which allow the inpcb to
be properly unlocked as needed. in_pcbrele() is a wrapper around the
latter, and should probably go away at some point. This makes it
easier to use this weak reference model when holding only a read lock,
as will happen in the future.

This may well be safe to MFC, but some more KBI analysis is required.

Reviewed by: bz
MFC after: 3 weeks
Sponsored by: Juniper Networks, Inc.

A number of quite incremental refinements to struct inpcbinfo's definition:

(1) Add a locking guide for inpcbinfo.
(2) Annotate inpcbinfo fields with synchronisation information; not all
annotations are 100% satisfactory.
(3) Reorder inpcbinfo fields so that the lock is at the head of the
structure, and close to fields it protects.
(4) Sort fields that will eventually be hashlock/pcbgroup-related together
even though they remain locked by ipi_lock for now.

Reviewed by: bz
Sponsored by: Juniper Networks
X-MFC after: KBI analysis required

MFp4 CH=191470:

Move the ipport_tick_callout and related functions from ip_input.c
to in_pcb.c. The random source port allocation code has been merged
and is now local to in_pcb.c only.
Use a SYSINIT to get the callout started and no longer depend on
initialization from the inet code, which would not work in an IPv6
only setup.

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

Merge the two identical implementations for local port selections from
in_pcbbind_setup() and in6_pcbsetport() in a single in_pcb_lport().

MFC after: 2 weeks

Abstract out initialization of most aspects of struct inpcbinfo from
their calling contexts in {IP divert, raw IP sockets, TCP, UDP} and
create new helper functions: in_pcbinfo_init() and in_pcbinfo_destroy()
to do this work in a central spot. As inpcbinfo becomes more complex
due to ongoing work to add connection groups, this will reduce code
duplication.

MFC after: 1 month
Reviewed by: bz
Sponsored by: Juniper Networks

Wrap use of rw_try_upgrade() on pcbinfo with macro INP_INFO_TRY_UPGRADE()
to match other pcbinfo locking macros.

MFC after: 1 week

Add padding to struct inpcb, missed during our padding sweep earlier in
the release cycle.

Approved by: re (kensmith)

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)

After cleaning up rt_tables from vnet.h and cleaning up opt_route.h
a lot of files no longer need route.h either. Garbage collect them.
While here remove now unneeded vnet.h #includes as well.

- Rename IP_NONLOCALOK IP socket option to IP_BINDANY, to be more consistent
with OpenBSD (and BSD/OS originally). We can't easly do it SOL_SOCKET option
as there is no more space for more SOL_SOCKET options, but this option also
fits better as an IP socket option, it seems.
- Implement this functionality also for IPv6 and RAW IP sockets.
- Always compile it in (don't use additional kernel options).
- Remove sysctl to turn this functionality on and off.
- Introduce new privilege - PRIV_NETINET_BINDANY, which allows to use this
functionality (currently only unjail root can use it).

Discussed with: julian, adrian, jhb, rwatson, kmacy

Staticize two functions not used outside of in_pcb.c: in_pcbremlists() and
db_print_inpcb().

MFC after: 1 month

Permit buiding kernels with options VIMAGE, restricted to only a single
active network stack instance. Turning on options VIMAGE at compile
time yields the following changes relative to default kernel build:

1) V_ accessor macros for virtualized variables resolve to structure
fields via base pointers, instead of being resolved as fields in global
structs or plain global variables. As an example, V_ifnet becomes:

options VIMAGE: ((struct vnet_net *) vnet_net)->_ifnet
default build: vnet_net_0._ifnet
options VIMAGE_GLOBALS: ifnet

2) INIT_VNET_* macros will declare and set up base pointers to be used
by V_ accessor macros, instead of resolving to whitespace:

INIT_VNET_NET(ifp->if_vnet); becomes

struct vnet_net *vnet_net = (ifp->if_vnet)->mod_data[VNET_MOD_NET];

3) Memory for vnet modules registered via vnet_mod_register() is now
allocated at run time in sys/kern/kern_vimage.c, instead of per vnet
module structs being declared as globals. If required, vnet modules
can now request the framework to provide them with allocated bzeroed
memory by filling in the vmi_size field in their vmi_modinfo structures.

4) structs socket, ifnet, inpcbinfo, tcpcb and syncache_head are
extended to hold a pointer to the parent vnet. options VIMAGE builds
will fill in those fields as required.

5) curvnet is introduced as a new global variable in options VIMAGE
builds, always pointing to the default and only struct vnet.

6) struct sysctl_oid has been extended with additional two fields to
store major and minor virtualization module identifiers, oid_v_subs and
oid_v_mod. SYSCTL_V_* family of macros will fill in those fields
accordingly, and store the offset in the appropriate vnet container
struct in oid_arg1.
In sysctl handlers dealing with virtualized sysctls, the
SYSCTL_RESOLVE_V_ARG1() macro will compute the address of the target
variable and make it available in arg1 variable for further processing.

Unused fields in structs vnet_inet, vnet_inet6 and vnet_ipfw have
been deleted.

Reviewed by: bz, rwatson
Approved by: julian (mentor)

s/void/void */

restore spare pointers for MFCing

- convert pspare pointers in inpcb to an llentry and rtentry cache
- add flags to indicate their validity

- add second flags field to to inpcb
- update comments in vflag

provide additional convenience macros for inpcb locking (upgrade, downgrade, exclusive)

Import "flowid" support for serializing flows across transmit queues

Reviewed by: rwatson and jeli

Correct a number of evolved problems with inp_vflag and inp_flags:
certain flags that should have been in inp_flags ended up in inp_vflag,
meaning that they were inconsistently locked, and in one case,
interpreted. Move the following flags from inp_vflag to gaps in the
inp_flags space (and clean up the inp_flags constants to make gaps
more obvious to future takers):

INP_TIMEWAIT
INP_SOCKREF
INP_ONESBCAST
INP_DROPPED

Some aspects of this change have no effect on kernel ABI at all, as these
are UDP/TCP/IP-internal uses; however, netstat and sockstat detect
INP_TIMEWAIT when listing TCP sockets, so any MFC will need to take this
into account.

MFC after: 1 week (or after dependencies are MFC'd)
Reviewed by: bz

Add INP_INHASHLIST flag for inpcb->inp_flags to indicate whether
or not the inpcb is currenty on various hash lookup lists, rather
than using (lport != 0) to detect this. This means that the full
4-tuple of a connection can be retained after close, which should
lead to more sensible netstat output in the window between TCP
close and socket close.

MFC after: 2 weeks

Remove unused v6 macro aliases for inpcb fields:

in6p_ip6_nxt
in6p_vflag
in6p_flags
in6p_socket
in6p_lport
in6p_fport
in6p_ppcb

Remove unused v6 macro aliases for inpcb flags:

IN6P_HIGHPORT
IN6P_LOWPORT
IN6P_ANONPORT
IN6P_RECVIF
IN6P_MTUDISC
IN6P_FAITH
IN6P_CONTROLOPTS

References to in6p_lport and in6_fport in sockstat are also replaced with
normal inp_lport and inp_fport references.

MFC after: 3 days
Reviewed by: bz

Remove now-unused INP_UNMAPPABLEOPTS.

MFC after: 3 days
Discussed with: bz

Implement a new IP option (not compiled/enabled by default) to allow
applications to specify a non-local IP address when bind()'ing a socket
to a local endpoint.

This allows applications to spoof the client IP address of connections
if (obviously!) they somehow are able to receive the traffic normally
destined to said clients.

This patch doesn't include any changes to ipfw or the bridging code to
redirect the client traffic through the PCB checks so TCP gets a shot
at it. The normal behaviour is that packets with a non-local destination
IP address are not handled locally. This can be dealth with some IPFW hackery;
modifications to IPFW to make this less hacky will occur in subsequent
commmits.

Thanks to Julian Elischer and others at Ironport. This work was approved
and donated before Cisco acquired them.

Obtained from: Julian Elischer and others
MFC after: 2 weeks

Another step assimilating IPv[46] PCB code:
normalize IN6P_* compat flags usage to their equialent
INP_* counterpart.

Discussed with: rwatson
Reviewed by: rwatson
MFC after: 4 weeks

Use inc_flags instead of the inc_isipv6 alias which so far
had been the only flag with random usage patterns.
Switch inc_flags to be used as a real bit field by using
INC_ISIPV6 with bitops to check for the 'isipv6' condition.

While here fix a place or two where in case of v4 inc_flags
were not properly initialized before.[1]

Found by: rwatson during review [1]
Discussed with: rwatson
Reviewed by: rwatson
MFC after: 4 weeks

Put a global variables, which were virtualized but formerly
missed under VIMAGE_GLOBAL.

Start putting the extern declarations of the virtualized globals
under VIMAGE_GLOBAL as the globals themsevles are already.
This will help by the time when we are going to remove the globals
entirely.

While there garbage collect a few dead externs from ip6_var.h.

Sponsored by: The FreeBSD Foundation

Update comment on INP_TIMEWAIT to say what it's about, as we caution
regarding the misplacement of flags in inp_vflag in an earlier comment.

MFC after: pretty soon

Move macros defining flags and shortcus to nested structure fields in
inpcbinfo below the structure definition in order to make inpcbinfo
fit on a single printed page; related style tweaks.

MFC after: pretty soon

Add a reference count to struct inpcb, which may be explicitly
incremented using in_pcbref(), and decremented using in_pcbfree()
or inpcbrele(). Protocols using only current in_pcballoc() and
in_pcbfree() calls will see the same semantics, but it is now
possible for TCP to call in_pcbref() and in_pcbrele() to prevent
an inpcb from being freed when both tcbinfo and per-inpcb locks
are released. This makes it possible to safely transition from
holding only the inpcb lock to both tcbinfo and inpcb lock
without re-looking up a connection in the input path, timer
path, etc.

Notice that in_pcbrele() does not unlock the connection after
decrementing the refcount, if the connection remains, so that
the caller can continue to use it; in_pcbrele() returns a flag
indicating whether or not the inpcb pointer is still valid, and
in_pcbfee() is now a simple wrapper around in_pcbrele().

MFC after: 1 month
Discussed with: bz, kmacy
Reviewed by: bz, gnn, kmacy
Tested by: kmacy

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

Bring over the change switching from using sequential to random
ephemeral port allocation as implemented in netinet/in_pcb.c rev. 1.143
(initially from OpenBSD) and follow-up commits during the last four and
a half years including rev. 1.157, 1.162 and 1.199.
This now is relying on the same infrastructure as has been implemented
in in_pcb.c since rev. 1.199.

Reviewed by: silby, rpaulo, mlaier
MFC after: 2 months

Cache so_cred as inp_cred in the inpcb.
This means that inp_cred is always there, even after the socket
has gone away. It also means that it is constant for the lifetime
of the inp.
Both facts lead to simpler code and possibly less locking.

Suggested by: rwatson
Reviewed by: rwatson
MFC after: 6 weeks
X-MFC Note: use a inp_pspare for inp_cred

Fix typo in comment.

MFC after: 3 days

Minor white space tweaks.

MFC after: 1 week

Trying to fix compilation bustage:
- removing 'const' qualifier from an input parameter to conform to the type
required by rw_assert();
- using in_addr->s_addr to retrive 32 bits address value.

Observed by: tinderbox

make new accessor functions consistent with existing style

add inpcb accessor functions for fields needed by TOE devices

Merge last of a series of rwlock conversion changes to UDP, which
completes the move to a fully parallel UDP transmit path by using
global read, rather than write, locking of inpcbinfo in further
semi-connected cases:

- Add macros to allow try-locking of inpcb and inpcbinfo.
- Always acquire an incpcb read lock in udp_output(), which stablizes the
local inpcb address and port bindings in order to determine what further
locking is required:
- If the inpcb is currently not bound (at all) and are implicitly
connecting, we require inpcbinfo and inpcb write locks, so drop the
read lock and re-acquire.
- If the inpcb is bound for at least one of the port or address, but an
explicit source or destination is requested, trylock the inpcbinfo
lock, and if that fails, drop the inpcb lock, lock the global lock,
and relock the inpcb lock.
- Otherwise, no further locking is required (common case).
- Update comments.

In practice, this means that the vast majority of consumers of UDP sockets
will not acquire any exclusive locks at the socket or UDP levels of the
network stack. This leads to a marked performance improvement in several
important workloads, including BIND, nsd, and memcached over UDP, as well
as significant improvements in pps microbenchmarks.

The plan is to MFC all of the rwlock changes to RELENG_7 once they have
settled for a weeks in the tree.

Tested by: ps, kris (older revision), bde
MFC after: 3 weeks

Pass the ucred along into in{,6}_pcblookup_local for upcoming
prison checks.

Reviewed by: rwatson

For consistency take lport as u_short in in{,6}_pcblookup_local.
All callers either pass in an u_short or u_int16_t.

Reviewed by: rwatson

Provide some initial chicken-scratching annotations of locking for
struct inpcb.

Prodded by: bz
MFC after: 3 days

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

Convert pcbinfo and inpcb mutexes to rwlocks, and modify macros to
explicitly select write locking for all use of the inpcb mutex.
Update some pcbinfo lock assertions to assert locked rather than
write-locked, although in practice almost all uses of the pcbinfo
rwlock main exclusive, and all instances of inpcb lock acquisition
are exclusive.

This change should introduce (ideally) little functional change.
However, it lays the groundwork for significantly increased
parallelism in the TCP/IP code.

MFC after: 3 months
Tested by: kris (superset of committered patch)

change inp_wlock_assert to inp_lock_assert

Label inp as unused in the non-INVARIANTS case

Insulate inpcb consumers outside the stack from the lock type and offset within the pcb by adding accessor functions.

Reviewed by: rwatson
MFC after: 3 weeks

Add padding for anticipated functionality
- vimage
- TOE
- multiq
- host rtentry caching

Rename spare used by 80211 to if_llsoftc

Reviewed by: rwatson, gnn
MFC after: 1 day

Remove the now-unused NET_{LOCK,UNLOCK,ASSERT}_GIANT() macros, which
previously conditionally acquired Giant based on debug.mpsafenet. As that
has now been removed, they are no longer required. Removing them
significantly simplifies error-handling in the socket layer, eliminated
quite a bit of unwinding of locking in error cases.

While here clean up the now unneeded opt_net.h, which previously was used
for the NET_WITH_GIANT kernel option. Clean up some related gotos for
consistency.

Reviewed by: bz, csjp
Tested by: kris
Approved by: re (kensmith)

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

Reduce network stack oddness: implement .pru_sockaddr and .pru_peeraddr
protocol entry points using functions named proto_getsockaddr and
proto_getpeeraddr rather than proto_setsockaddr and proto_setpeeraddr.
While it's true that sockaddrs are allocated and set, the net effect is
to retrieve (get) the socket address or peer address from a socket, not
set it, so align names to that intent.

Remove unused pcbinfo arguments to in_setsockaddr() and
in_setpeeraddr().

Rename some fields of struct inpcbinfo to have the ipi_ prefix,
consistent with the naming of other structure field members, and
reducing improper grep matches. Clean up and comment structure
fields in structure definition.

Add INP_INFO_UNLOCK_ASSERT() and use it in tcp_input(). Also add some
further INP_INFO_WLOCK_ASSERT() while there.

Some local and style(9) cleanups.

Remove stale comment about not enabling inpcb and inpcbinfo lock assertions
when IPv6 is enabled.

MFC after: 3 days

Add "show inpcb", "show tcpcb" DDB commands, which should come in handy
for debugging sblock and other network panics.

Remove unused inp6_ifindex field from inpcb, as well as unused macro
shortcut for it.

Remove unused in6p_ip6_hlim macro shortcut for non-present
inp_depend6.inp6_hlim field in the inpcb.

Fix race conditions on enumerating pcb lists by moving the initialization
( and where appropriate the destruction) of the pcb mutex to the init/finit
functions of the pcb zones.
This allows locking of the pcb entries and race condition free comparison
of the generation count.
Rearrange locking a bit to avoid extra locking operation to update the generation
count in in_pcballoc(). (in_pcballoc now returns the pcb locked)

I am planning to convert pcb list handling from a type safe to a reference count
model soon. ( As this allows really freeing the PCBs)

Reviewed by: rwatson@, mohans@
MFC after: 1 week

Abstract inpcb drop logic, previously just setting of INP_DROPPED in TCP,
into in_pcbdrop(). Expand logic to detach the inpcb from its bound
address/port so that dropping a TCP connection releases the inpcb resource
reservation, which since the introduction of socket/pcb reference count
updates, has been persisting until the socket closed rather than being
released implicitly due to prior freeing of the inpcb on TCP drop.

MFC after: 3 months

Change inp_ppcb from caddr_t to void *, fix/remove associated related
casts.

Consistently use intotw() to cast inp_ppcb pointers to struct tcptw *
pointers.

Consistently use intotcpcb() to cast inp_ppcb pointers to struct tcpcb *
pointers.

Don't assign tp to the results to intotcpcb() during variable declation
at the top of functions, as that is before the asserts relating to
locking have been performed. Do this later in the function after
appropriate assertions have run to allow that operation to be conisdered
safe.

MFC after: 3 months

Break out in_pcbdetach() into two functions:

- in_pcbdetach(), which removes the link between an inpcb and its
socket.

- in_pcbfree(), which frees a detached pcb.

Unlike the previous in_pcbdetach(), neither of these functions will
attempt to conditionally free the socket, as they are responsible only
for managing in_pcb memory. Mirror these changes into in6_pcbdetach()
by breaking it into in6_pcbdetach() and in6_pcbfree().

While here, eliminate undesired checks for NULL inpcb pointers in
sockets, as we will now have as an invariant that sockets will always
have valid so_pcb pointers.

MFC after: 3 months

Define two new inpcb flags in the inp_vflag field, which for whatever
reason, seems to be where new flags are getting defined:

INP_DROPPED - The protocol has terminated this connection and the socket
is not reusable: when the socket code enters the protocol,
an error is immediately returned. This will substitute for
NULLing the so_pcb socket field, helping to implement the
invariant that all valid sockets have valid pcb's in TCP.

INP_SOCKREF - The protocol has become the owner of the socket reference,
and will need to free it when freeing the pcb, which will
be used when a TCP socket is closed but still has queued
data.

MFC after: 1 month

Minor style tweak: tab after #define, not space.

MFC after: 1 month

Make net.inet.ip.portrange.reservedhigh and
net.inet.ip.portrange.reservedlow apply to IPv6 aswell as IPv4.

We could have made new sysctls for IPv6, but that potentially makes
things complicated for mapped addresses. This seems like the least
confusing option and least likely to cause obscure problems in the
future.

This change makes the mac_portacl module useful with IPv6 apps.

Reviewed by: ume
MFC after: 1 month

Implement IP_DONTFRAG IP socket option enabling the Don't Fragment
flag on IP packets. Currently this option is only repected on udp
and raw ip sockets. On tcp sockets the DF flag is controlled by the
path MTU discovery option.

Sending a packet larger than the MTU size of the egress interface
returns an EMSGSIZE error.

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

Add socketoption IP_MINTTL. May be used to set the minimum acceptable
TTL a packet must have when received on a socket. All packets with a
lower TTL are silently dropped. Works on already connected/connecting
and listening sockets for RAW/UDP/TCP.

This option is only really useful when set to 255 preventing packets
from outside the directly connected networks reaching local listeners
on sockets.

Allows userland implementation of 'The Generalized TTL Security Mechanism
(GTSM)' according to RFC3682. Examples of such use include the Cisco IOS
BGP implementation command "neighbor ttl-security".

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

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

Port randomization leads to extremely fast port reuse at high
connection rates, which is causing problems for some users.

To retain the security advantage of random ports and ensure
correct operation for high connection rate users, disable
port randomization during periods of high connection rates.

Whenever the connection rate exceeds randomcps (10 by default),
randomization will be disabled for randomtime (45 by default)
seconds. These thresholds may be tuned via sysctl.

Many thanks to Igor Sysoev, who proved the necessity of this
change and tested many preliminary versions of the patch.

MFC After: 20 seconds

Define INP_UNLOCK_ASSERT() to assert that an inpcb is unlocked.

MFC after: 2 weeks

Add a macro for the destruction of INP_INFO_LOCK's used by loadable modules.

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>

Now that IPv6 performs basic in6pcb and inpcb locking, enable inpcb
lock assertions even if IPv6 is compiled into the kernel. Previously,
inclusion of IPv6 and locking assertions would result in a rapid
assertion failure as IPv6 was not properly locking inpcbs.

Remove erroneous semicolons.

When asserting non-Giant locks in the network stack, also assert
Giant if debug.mpsafenet=0, as any points that require synchronization
in the SMPng world also required it in the Giant-world:

- inpcb locks (including IPv6)
- inpcbinfo locks (including IPv6)
- dummynet subsystem lock
- ipfw2 subsystem lock

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

Reduce 'td' argument to 'cred' (struct ucred) argument in those functions:
- in_pcbbind(),
- in_pcbbind_setup(),
- in_pcbconnect(),
- in_pcbconnect_setup(),
- in6_pcbbind(),
- in6_pcbconnect(),
- in6_pcbsetport().
"It should simplify/clarify things a great deal." --rwatson

Requested by: rwatson
Reviewed by: rwatson, ume

Remove unused argument.

Reviewed by: ume

Remove unused function.
It was used in FreeBSD 4.x, but now we're using cr_canseesocket().

Split the "inp" mutex class into separate classes for each of divert,
raw, tcp, udp, raw6, and udp6 sockets to avoid spurious witness
complaints.

Reviewed by: rwatson
Approved by: re (rwatson)

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)

Introduce a MAC label reference in 'struct inpcb', which caches
the MAC label referenced from 'struct socket' in the IPv4 and
IPv6-based protocols. This permits MAC labels to be checked during
network delivery operations without dereferencing inp->inp_socket
to get to so->so_label, which will eventually avoid our having to
grab the socket lock during delivery at the network layer.

This change introduces 'struct inpcb' as a labeled object to the
MAC Framework, along with the normal circus of entry points:
initialization, creation from socket, destruction, as well as a
delivery access control check.

For most policies, the inpcb label will simply be a cache of the
socket label, so a new protocol switch method is introduced,
pr_sosetlabel() to notify protocols that the socket layer label
has been updated so that the cache can be updated while holding
appropriate locks. Most protocols implement this using
pru_sosetlabel_null(), but IPv4/IPv6 protocols using inpcbs use
the the worker function in_pcbsosetlabel(), which calls into the
MAC Framework to perform a cache update.

Biba, LOMAC, and MLS implement these entry points, as do the stub
policy, and test policy.

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

add locking assertions that turn into noops if INET6 is configured;
this is necessary because the ipv6 code shares the in_pcb code with
ipv4 but (presently) lacks proper locking

Supported by: FreeBSD Foundation

correct tab and order.

Switch Advanced Sockets API for IPv6 from RFC2292 to RFC3542
(aka RFC2292bis). Though I believe this commit doesn't break
backward compatibility againt existing binaries, it breaks
backward compatibility of API.
Now, the applications which use Advanced Sockets API such as
telnet, ping6, mld6query and traceroute6 use RFC3542 API.

Obtained from: KAME

Add the IP_ONESBCAST option, to enable undirected IP broadcasts to be sent on
specific interfaces. This is required by aodvd, and may in future help us
in getting rid of the requirement for BPF from our import of isc-dhcp.

Suggested by: fenestro
Obtained from: BSD/OS
Reviewed by: mini, sam
Approved by: jake (mentor)

IP_RECVTTL socket option.

Reviewed by: Stuart Cheshire <cheshire@apple.com>

Back out support for RFC3514.

RFC3514 poses an unacceptale risk to compliant systems.

Implement support for RFC 3514 (The Security Flag in the IPv4 Header).
(See: ftp://ftp.rfc-editor.org/in-notes/rfc3514.txt)

This fulfills the host requirements for userland support by
way of the setsockopt() IP_EVIL_INTENT message.

There are three sysctl tunables provided to govern system behavior.

net.inet.ip.rfc3514:

Enables support for rfc3514. As this is an
Informational RFC and support is not yet widespread
this option is disabled by default.

net.inet.ip.hear_no_evil

If set the host will discard all received evil packets.

net.inet.ip.speak_no_evil

If set the host will discard all transmitted evil packets.

The IP statistics counter 'ips_evil' (available via 'netstat') provides
information on the number of 'evil' packets recieved.

For reference, the '-E' option to 'ping' has been provided to demonstrate
and test the implementation.

Add a TCP TIMEWAIT state which uses less space than a fullblown TCP
control block. Allow the socket and tcpcb structures to be freed
earlier than inpcb. Update code to understand an inp w/o a socket.

Reviewed by: hsu, silby, jayanth
Sponsored by: DARPA, NAI Labs

Turn off duplicate lock checking for inp locks because udp_input()
intentionally locks two inp records simultaneously.

Replace in_pcbladdr() with a more generic inner subroutine for
in_pcbconnect() called in_pcbconnect_setup(). This version performs
all of the functions of in_pcbconnect() except for the final
committing of changes to the PCB. In the case of an EADDRINUSE error
it can also provide to the caller the PCB of the duplicate connection,
avoiding an extra in_pcblookup_hash() lookup in tcp_connect().

This change will allow the "temporary connect" hack in udp_output()
to be removed and is part of the preparation for adding the
IP_SENDSRCADDR control message.

Discussed on: -net
Approved by: re

Split out most of the logic from in_pcbbind() into a new function
called in_pcbbind_setup() that does everything except commit the
changes to the PCB. There should be no functional change here, but
in_pcbbind_setup() will be used by the soon-to-appear IP_SENDSRCADDR
control message implementation to check or allocate the source
address and port.

Discussed on: -net
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

Fixed namespace pollution in uma changes:
- use `struct uma_zone *' instead of uma_zone_t, so that <sys/uma.h> isn't
a prerequisite.
- don't include <sys/uma.h>.
Namespace pollution makes "opaque" types like uma_zone_t perfectly
non-opaque. Such types should never be used (see style(9)).

Fixed subsequently grwon dependencies of this header on its own pollution:
- include <sys/_mutex.h> and its prerequisite <sys/_lock.h> instead of
depending on namespace pollution 2 layers deep in <sys/uma.h>.

Create new functions in_sockaddr(), in6_sockaddr(), and
in6_v4mapsin6_sockaddr() which allocate the appropriate sockaddr_in*
structure and initialize it with the address and port information passed
as arguments. Use calls to these new functions to replace code that is
replicated multiple times in in_setsockaddr(), in_setpeeraddr(),
in6_setsockaddr(), in6_setpeeraddr(), in6_mapped_sockaddr(), and
in6_mapped_peeraddr(). Inline COMMON_END in tcp_usr_accept() so that
we can call in_sockaddr() with temporary copies of the address and port
after the PCB is unlocked.

Fix the lock violation in tcp6_usr_accept() (caused by calling MALLOC()
inside in6_mapped_peeraddr() while the PCB is locked) by changing
the implementation of tcp6_usr_accept() to match tcp_usr_accept().

Reviewed by: suz

do not refer to IN6P_BINDV6ONLY anymore.

Obtained from: KAME
MFC after: 1 week

Notify functions can destroy the pcb, so they have to return an
indication of whether this happenned so the calling function
knows whether or not to unlock the pcb.

Submitted by: Jennifer Yang (yangjihui@yahoo.com)
Bug reported by: Sid Carter (sidcarter@symonds.net)

Lock up inpcb.

Submitted by: Jennifer Yang <yangjihui@yahoo.com>

Change the first argument of prison_xinpcb() to be a thread pointer instead
of a proc pointer so that prison_xinpcb() can use td_ucred.

Fixed some style bugs in the removal of __P(()). Continuation lines
were not outdented to preserve non-KNF lining up of code with parentheses.
Switch to KNF formatting.

Switch vm_zone.h with uma.h. Change over to uma interfaces.

Remove __P.

This is the first part of the new kernel memory allocator. This replaces
malloc(9) and vm_zone with a slab like allocator.

Reviewed by: arch@

Document what inpcb->inp_vflag is for.

Submitted by: Marco Molteni <molter@tin.it>

Add include of net/route.h, as structures moved around due to the
syncache rely on 'struct route' being defined. This fixes the
LINT build some.

Introduce a syncache, which enables FreeBSD to withstand a SYN flood
DoS in an improved fashion over the existing code.

Reviewed by: silby (in a previous iteration)
Sponsored by: DARPA, NAI Labs

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

When running aplication joined multicast address,
removing network card, and kill aplication.
imo_membership[].inm_ifp refer interface pointer
after removing interface.
When kill aplication, release socket,and imo_membership.
imo_membership use already not exist interface pointer.
Then, kernel panic.

PR: 29345
Submitted by: Inoue Yuichi <inoue@nd.net.fujitsu.co.jp>
Obtained from: KAME
MFC after: 3 days

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

Remove in_pcbnotify and use in_pcblookup_hash to find the cb directly.

For TCP, verify that the sequence number in the ICMP packet falls within
the tcp receive window before performing any actions indicated by the
icmp packet.

Clean up some layering violations (access to tcp internals from in_pcb)

Redo the security update done in rev 1.54 of src/sys/netinet/tcp_subr.c
and 1.84 of src/sys/netinet/udp_usrreq.c

The changes broken down:

- remove 0 as a wildcard for addresses and port numbers in
src/sys/netinet/in_pcb.c:in_pcbnotify()
- add src/sys/netinet/in_pcb.c:in_pcbnotifyall() used to notify
all sessions with the specific remote address.
- change
- src/sys/netinet/udp_usrreq.c:udp_ctlinput()
- src/sys/netinet/tcp_subr.c:tcp_ctlinput()
to use in_pcbnotifyall() to notify multiple sessions, instead of
using in_pcbnotify() with 0 as src address and as port numbers.
- remove check for src port == 0 in
- src/sys/netinet/tcp_subr.c:tcp_ctlinput()
- src/sys/netinet/udp_usrreq.c:udp_ctlinput()
as they are no longer needed.
- move handling of redirects and host dead from in_pcbnotify() to
udp_ctlinput() and tcp_ctlinput(), so they will call
in_pcbnotifyall() to notify all sessions with the specific
remote address.

Approved by: jlemon
Inspired by: NetBSD

Update the "icmp_admin_prohib_like_rst" code to check the tcp-window and
to be configurable with respect to acting only in SYN or in all TCP states.

PR: 23665
Submitted by: Jesper Skriver <jesper@skriver.dk>

Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by: msmith and others

Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by: phk
Reviewed by: phk
Approved by: mdodd

Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.

udp IPv6 support, IPv6/IPv4 tunneling support in kernel,
packet divert at kernel for IPv6/IPv4 translater daemon

This includes queue related patch submitted by jburkhol@home.com.

Submitted by: queue related patch from jburkhol@home.com
Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project

KAME netinet6 basic part(no IPsec,no V6 Multicast Forwarding, no UDP/TCP
for IPv6 yet)

With this patch, you can assigne IPv6 addr automatically, and can reply to
IPv6 ping.

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

KAME related header files additions and merges.
(only those which don't affect c source files so much)

Reviewed by: cvs-committers
Obtained from: KAME project

$Id$ -> $FreeBSD$

This Implements the mumbled about "Jail" feature.

This is a seriously beefed up chroot kind of thing. The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.

For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact: "real virtual servers".

Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.

Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.

It generally does what one would expect, but setting up a jail
still takes a little knowledge.

A few notes:

I have no scripts for setting up a jail, don't ask me for them.

The IP number should be an alias on one of the interfaces.

mount a /proc in each jail, it will make ps more useable.

/proc/<pid>/status tells the hostname of the prison for
jailed processes.

Quotas are only sensible if you have a mountpoint per prison.

There are no privisions for stopping resource-hogging.

Some "#ifdef INET" and similar may be missing (send patches!)

If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!

Tools, comments, patches & documentation most welcome.

Have fun...

Sponsored by: http://www.rndassociates.com/
Run for almost a year by: http://www.servetheweb.com/

Convert socket structures to be type-stable and add a version number.

Define a parameter which indicates the maximum number of sockets in a
system, and use this to size the zone allocators used for sockets and
for certain PCBs.

Convert PF_LOCAL PCB structures to be type-stable and add a version number.

Define an external format for infomation about socket structures and use
it in several places.

Define a mechanism to get all PF_LOCAL and PF_INET PCB lists through
sysctl(3) without blocking network interrupts for an unreasonable
length of time. This probably still has some bugs and/or race
conditions, but it seems to work well enough on my machines.

It is now possible for `netstat' to get almost all of its information
via the sysctl(3) interface rather than reading kmem (changes to follow).

Fixed style bugs (mostly) in previous commit.

Use the zone allocator to allocate inpcbs and tcpcbs. Each protocol creates
its own zone; this is used particularly by TCP which allocates both inpcb and
tcpcb in a single allocation. (Some hackery ensures that the tcpcb is
reasonably aligned.) Also keep track of the number of pcbs of each type
allocated, and keep a generation count (instance version number) for future
use.

Improved connection establishment performance by doing local port lookups via
a hashed port list. In the new scheme, in_pcblookup() goes away and is
replaced by a new routine, in_pcblookup_local() for doing the local port
check. Note that this implementation is space inefficient in that the PCB
struct is now too large to fit into 128 bytes. I might deal with this in the
future by using the new zone allocator, but I wanted these changes to be
extensively tested in their current form first.

Also:
1) Fixed off-by-one errors in the port lookup loops in in_pcbbind().
2) Got rid of some unneeded rehashing. Adding a new routine, in_pcbinshash()
to do the initialial hash insertion.
3) Renamed in_pcblookuphash() to in_pcblookup_hash() for easier readability.
4) Added a new routine, in_pcbremlists() to remove the PCB from the various
hash lists.
5) Added/deleted comments where appropriate.
6) Removed unnecessary splnet() locking. In general, the PCB functions should
be called at splnet()...there are unfortunately a few exceptions, however.
7) Reorganized a few structs for better cache line behavior.
8) Killed my TCP_ACK_HACK kludge. It may come back in a different form in
the future, however.

These changes have been tested on wcarchive for more than a month. In tests
done here, connection establishment overhead is reduced by more than 50
times, thus getting rid of one of the major networking scalability problems.

Still to do: make tcp_fastimo/tcp_slowtimo scale well for systems with a
large number of connections. tcp_fastimo is easy; tcp_slowtimo is difficult.

WARNING: Anything that knows about inpcb and tcpcb structs will have to be
recompiled; at the very least, this includes netstat(1).

Fix all areas of the system (or at least all those in LINT) to avoid storing
socket addresses in mbufs. (Socket buffers are the one exception.) A number
of kernel APIs needed to get fixed in order to make this happen. Also,
fix three protocol families which kept PCBs in mbufs to not malloc them
instead. Delete some old compatibility cruft while we're at it, and add
some new routines in the in_cksum family.

The long-awaited mega-massive-network-code- cleanup. Part I.

This commit includes the following changes:
1) Old-style (pr_usrreq()) protocols are no longer supported, the compatibility
glue for them is deleted, and the kernel will panic on boot if any are compiled
in.

2) Certain protocol entry points are modified to take a process structure,
so they they can easily tell whether or not it is possible to sleep, and
also to access credentials.

3) SS_PRIV is no more, and with it goes the SO_PRIVSTATE setsockopt()
call. Protocols should use the process pointer they are now passed.

4) The PF_LOCAL and PF_ROUTE families have been updated to use the new
style, as has the `raw' skeleton family.

5) PF_LOCAL sockets now obey the process's umask when creating a socket
in the filesystem.

As a result, LINT is now broken. I'm hoping that some enterprising hacker
with a bit more time will either make the broken bits work (should be
easy for netipx) or dike them out.

Reorganize elements of the inpcb struct to take better advantage of
cache lines. Removed the struct ip proto since only a couple of chars
were actually being used in it. Changed the order of compares in the
PCB hash lookup to take advantage of partial cache line fills (on PPro).

Discussed-with: wollman

Improved performance of hash algorithm while (hopefully) not reducing
the quality of the hash distribution. This does not fix a problem dealing
with poor distribution when using lots of IP aliases and listening
on the same port on every one of them...some other day perhaps; fixing
that requires significant code changes.
The use of xor was inspired by David S. Miller <davem@jenolan.rutgers.edu>

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

Convert raw IP from mondo-switch-statement-from-Hell to
pr_usrreqs. Collapse duplicates with udp_usrreq.c and
tcp_usrreq.c (calling the generic routines in uipc_socket2.c and
in_pcb.c). Calling sockaddr()_ or peeraddr() on a detached
socket now traps, rather than harmlessly returning an error; this
should never happen. Allow the raw IP buffer sizes to be
controlled via sysctl.

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.

Add the IP_RECVIF socket option, which supplies a packet's incoming interface
using a sockaddr_dl.

Fix the other packet-information socket options (SO_TIMESTAMP, IP_RECVDSTADDR)
to work for multicast UDP and raw sockets as well. (They previously only
worked for unicast UDP).

Fix braino on my part. When we have three different port ranges (default,
"high" and "secure"), we can't use a single variable to track the most
recently used port in all three ranges.. :-] This caused the next
transient port to be allocated from the start of the range more often than
it should.

Improved in_pcblookuphash() to support wildcarding, and changed relavent
callers of it to take advantage of this. This reduces new connection
request overhead in the face of a large number of PCBs in the system.
Thanks to David Filo <filo@yahoo.com> for suggesting this and providing
a sample implementation (which wasn't used, but showed that it could be
done).

Reviewed by: wollman

Mark sockets where the kernel chose the port# for.
This can be used by netstat to behave more intelligently.

Make the default behavior of local port assignment match traditional
systems (my last change did not mix well with some firewall
configurations). As much as I dislike firewalls, this is one thing I
I was not prepared to break by default.. :-)

Allow the user to nominate one of three ranges of port numbers as
candidates for selecting a local address to replace a zero port number.
The ranges are selected via a setsockopt(s, IPPROTO_IP, IP_PORTRANGE, &arg)
call. The three ranges are: default, high (to bypass firewalls) and
low (to get a port below 1024).

The default and high port ranges are sysctl settable under sysctl
net.inet.ip.portrange.*

This code also fixes a potential deadlock if the system accidently ran out
of local port addresses. It'd drop into an infinite while loop.

The secure port selection (for root) should reduce overheads and increase
reliability of rlogin/rlogind/rsh/rshd if they are modified to take
advantage of it.

Partly suggested by: pst
Reviewed by: wollman

Added explicit include of <sys/queue.h>. Currently, some things only
compile because <vm/vm.h> happens to be gratuitously included before
<netinet/in_pcb.h> and <vm/vm.h> happens to include <sys/queue.h>.

New style sysctl & staticize alot of stuff.

Backed out Jordan's #include of queue.h

#include <sys/queue.h> or die horribly.

Implemented PCB hashing. Includes new functions in_pcbinshash, in_pcbrehash,
and in_pcblookuphash.

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.

Made idempotent.

Submitted by: Paul

Added $Id$

The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch.

Reviewed by: Rodney W. Grimes
Submitted by: John Dyson and David Greenman

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