freebsd-skq/share/man/man4/if_ipsec.4
Andrey V. Elsukov fcf596178b Merge projects/ipsec into head/.
Small summary
 -------------

o Almost all IPsec releated code was moved into sys/netipsec.
o New kernel modules added: ipsec.ko and tcpmd5.ko. New kernel
  option IPSEC_SUPPORT added. It enables support for loading
  and unloading of ipsec.ko and tcpmd5.ko kernel modules.
o IPSEC_NAT_T option was removed. Now NAT-T support is enabled by
  default. The UDP_ENCAP_ESPINUDP_NON_IKE encapsulation type
  support was removed. Added TCP/UDP checksum handling for
  inbound packets that were decapsulated by transport mode SAs.
  setkey(8) modified to show run-time NAT-T configuration of SA.
o New network pseudo interface if_ipsec(4) added. For now it is
  build as part of ipsec.ko module (or with IPSEC kernel).
  It implements IPsec virtual tunnels to create route-based VPNs.
o The network stack now invokes IPsec functions using special
  methods. The only one header file <netipsec/ipsec_support.h>
  should be included to declare all the needed things to work
  with IPsec.
o All IPsec protocols handlers (ESP/AH/IPCOMP protosw) were removed.
  Now these protocols are handled directly via IPsec methods.
o TCP_SIGNATURE support was reworked to be more close to RFC.
o PF_KEY SADB was reworked:
  - now all security associations stored in the single SPI namespace,
    and all SAs MUST have unique SPI.
  - several hash tables added to speed up lookups in SADB.
  - SADB now uses rmlock to protect access, and concurrent threads
    can do SA lookups in the same time.
  - many PF_KEY message handlers were reworked to reflect changes
    in SADB.
  - SADB_UPDATE message was extended to support new PF_KEY headers:
    SADB_X_EXT_NEW_ADDRESS_SRC and SADB_X_EXT_NEW_ADDRESS_DST. They
    can be used by IKE daemon to change SA addresses.
o ipsecrequest and secpolicy structures were cardinally changed to
  avoid locking protection for ipsecrequest. Now we support
  only limited number (4) of bundled SAs, but they are supported
  for both INET and INET6.
o INPCB security policy cache was introduced. Each PCB now caches
  used security policies to avoid SP lookup for each packet.
o For inbound security policies added the mode, when the kernel does
  check for full history of applied IPsec transforms.
o References counting rules for security policies and security
  associations were changed. The proper SA locking added into xform
  code.
o xform code was also changed. Now it is possible to unregister xforms.
  tdb_xxx structures were changed and renamed to reflect changes in
  SADB/SPDB, and changed rules for locking and refcounting.

Reviewed by:	gnn, wblock
Obtained from:	Yandex LLC
Relnotes:	yes
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D9352
2017-02-06 08:49:57 +00:00

142 lines
4.4 KiB
Groff

.\" Copyright (c) 2017 Andrey V. Elsukov <ae@FreeBSD.org>
.\" All rights reserved.
.\"
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.\" $FreeBSD$
.\"
.Dd February 6, 2017
.Dt if_ipsec 4
.Os
.Sh NAME
.Nm if_ipsec
.Nd IPsec virtual tunneling interface
.Sh SYNOPSIS
The
.Cm if_ipsec
network interface is a part of the
.Fx
IPsec implementation.
To compile it into the kernel, place this line in the kernel
configuration file:
.Bd -ragged -offset indent
.Cd "options IPSEC"
.Ed
.Pp
It can also be loaded as part of the
.Cm ipsec
kernel module if the kernel was compiled with
.Bd -ragged -offset indent
.Cd "options IPSEC_SUPPORT"
.Ed
.Sh DESCRIPTION
The
.Nm
network interface is targeted for creating route-based VPNs.
It can tunnel IPv4 and IPv6 traffic over either IPv4 or IPv6 and secure
it with ESP.
.Pp
.Nm
interfaces are dynamically created and destroyed with the
.Xr ifconfig 8
.Cm create
and
.Cm destroy
subcommands.
The administrator must configure IPsec
.Cm tunnel
endpoint addresses.
These addresses will be used for the outer IP header of ESP packets.
The administrator can also configure the protocol and addresses for the inner
IP header with
.Xr ifconfig 8 ,
and modify the routing table to route the packets through the
.Nm
interface.
.Pp
When the
.Nm
interface is configured, it automatically creates special security policies.
These policies can be used to acquire security associations from the IKE daemon,
which are needed for establishing an IPsec tunnel.
It is also possible to create needed security associations manually with the
.Xr setkey 8
utility.
.Pp
Each
.Nm
interface has an additional numeric configuration option
.Cm reqid Ar id .
This
.Ar id
is used to distinguish traffic and security policies between several
.Nm
interfaces.
The
.Cm reqid
can be specified on interface creation and changed later.
If not specified, it is automatically assigned.
Note that changing
.Cm reqid
will lead to generation of new security policies, and this
may require creating new security associations.
.Sh EXAMPLES
The example below shows manual configuration of an IPsec tunnel
between two FreeBSD hosts.
Host A has the IP address 192.168.0.3, and host B has the IP address
192.168.0.5.
.Pp
On host A:
.Bd -literal -offset indent
ifconfig ipsec0 create reqid 100
ifconfig ipsec0 inet tunnel 192.168.0.3 192.168.0.5
ifconfig ipsec0 inet 172.16.0.3/16 172.16.0.5
setkey -c
add 192.168.0.3 192.168.0.5 esp 10000 -m tunnel -u 100 -E rijndael-cbc "VerySecureKey!!1";
add 192.168.0.5 192.168.0.3 esp 10001 -m tunnel -u 100 -E rijndael-cbc "VerySecureKey!!2";
^D
.Ed
.Pp
On host B:
.Bd -literal -offset indent
ifconfig ipsec0 create reqid 200
ifconfig ipsec0 inet tunnel 192.168.0.5 192.168.0.3
ifconfig ipsec0 inet 172.16.0.5/16 172.16.0.3
setkey -c
add 192.168.0.3 192.168.0.5 esp 10000 -m tunnel -u 200 -E rijndael-cbc "VerySecureKey!!1";
add 192.168.0.5 192.168.0.3 esp 10001 -m tunnel -u 200 -E rijndael-cbc "VerySecureKey!!2";
^D
.Ed
.Pp
Note the value 100 on host A and value 200 on host B are used as reqid.
The same value must be used as identifier of the policy entry in the
.Xr setkey 8
command.
.Sh SEE ALSO
.Xr gif 4 ,
.Xr gre 4 ,
.Xr ipsec 4 ,
.Xr ifconfig 8 ,
.Xr setkey 8
.Sh AUTHORS
.An Andrey V. Elsukov Aq Mt ae@FreeBSD.org