- fixed doxygen build
- seperates now in lib and charon
This commit is contained in:
Martin Willi
@@ -1,9 +1,10 @@
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strongSwans overall design
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============================
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/** @mainpage
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@section design strongSwans overall design
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IKEv1 and IKEv2 is handled in different keying daemons. The ole IKEv1 stuff is
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completely handled in pluto, as it was all the times. IKEv2 is handled in the
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new keying daemon, which is called charon.
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new keying daemon, which is called #charon.
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Daemon control is done over unix sockets. Pluto uses whack, as it did for years.
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Charon uses another socket interface, called stroke. Stroke uses another
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format as whack and therefore is not compatible to whack. The starter utility,
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@@ -13,6 +14,7 @@ Pluto uses starter for some commands, for other it uses the whack utility. To be
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as close to pluto as possible, charon has the same split up of commands to
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starter and stroke. All commands are wrapped together in the ipsec script, which
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allows transparent control of both daemons.
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@verbatim
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+-----------------------------------------+
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| ipsec |
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@@ -40,6 +42,7 @@ allows transparent control of both daemons.
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| RAW Sock | | UDP/500 |
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+----------+ +---------+
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@endverbatim
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Since IKEv2 uses the same port as IKEv1, both daemons must listen to UDP port
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500. Under Linux, there is no clean way to set up two sockets at the same port.
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To reslove this problem, charon uses a RAW socket, as they are used in network
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@@ -47,82 +50,7 @@ sniffers. An installed Linux Socket Filter (LSF) filters out all none-IKEv2
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traffic. Pluto receives any IKE message, independant of charons behavior.
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Therefore plutos behavior is changed to discard any IKEv2 traffic silently.
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To gain some reusability of the code, generic crypto and utility functions are
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separeted in a shared library, libstrongswan.
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IKEv2 keying daemon: charon
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=============================
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Threading modell
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------------------
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All IKEv2 stuff is handled in charon. It uses a newer and more flexible
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architecture than pluto. Charon uses a thread-pool, which allows parallel
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execution SA-management. Beside the thread-pool, there are some special purpose
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threads which do their job for the common health of the daemon.
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+------+
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| E Q |
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| v u |---+ +------+ +------+
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| e e | | | | | IKE- |
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| n u | +-----------+ | |--| SA |
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| t e | | | | I M | +------+
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+------------+ | - | | Scheduler | | K a |
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| receiver | +------+ | | | E n | +------+
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+----+-------+ +-----------+ | - a | | IKE- |
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| | +------+ | | S g |--| SA |
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+-------+--+ +-----| J Q |---+ +------------+ | A e | +------+
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-| socket | | o u | | | | - r |
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+-------+--+ | b e | | Thread- | | |
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| | - u | | Pool | | |
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+----+-------+ | e |------| |---| |
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| sender | +------+ +------------+ +------+
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+----+-------+
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| +------+
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| | S Q |
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| | e u |
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| | n e |
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+------------| d u |
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| - e |
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+--+---+
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The thread-pool is the heart of the architecture. It processes jobs from a
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(fully synchronized) job-queue. Mostly, a job is associated with a specific
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IKE SA. These IKE SAs are synchronized, only one thread can work one an IKE SA.
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This makes it unnecesary to use further synchronisation methods once a IKE SA
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is checked out. The (rather complex) synchronization of IKE SAs is completely
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done in the IKE SA manager.
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The sceduler is responsible for event firing. It waits until a event in the
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(fully synchronized) event-queue is ready for processing and pushes the event
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down to the job-queue. A thread form the pool will pick it up as quick as
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possible. Every thread can queue events or jobs. Furter, an event can place a
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packet in the send-queue. The sender thread waits for those packets and sends
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them over the wire, via the socket. The receiver does exactly the opposite of
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the sender. It waits on the socket, reads in packets an places them on the
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job-queue for further processing by a thread from the pool.
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There are even more threads, not drawn in the upper scheme. The stroke thread
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is responsible for reading and processessing commands from another process. The
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kernel interface thread handles communication from and to the kernel via a
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netlink socket. It waits for kernel events and processes them appropriately.
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configuration backends
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------------------------
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The configuration architecture for charon is complex, but is flexible and
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extensible. All configuration stuff is split up in multiple parts:
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connection Defines a connection between two hosts. Proposals define with
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wich algorithms a IKE SA should be set up.
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policy Defines the rules to apply ontop of a connection. A policy is
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defined between two IDs. Proposals and traffic selectors allow
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fine grained configuration of the CHILD SAs (AH and ESP) to set
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up.
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credential A credential is something used for authentication, such as a
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preshared key, a RSA private or public key, certificate, ...
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configuration The configuration itself handles daemon related configuration
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stuff, such as interface binding or logging settings.
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These configuration types are defined as interfaces, and are currently
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implemented only in the stroke class. Through the modular design, parts could be
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replaced with more powerful backends, such as a RADIUS server for the
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credentials, a SQL database for the connections, policy definitions on an LDAP
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server, and so on...
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*/
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@@ -3,3 +3,4 @@
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- intiating the same connection twice makes trouble
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- leak_detective gets confused from libpthread (invalid frees)
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- installing to many SAs in the kernel at the same time causes troubles. Threading issue?
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@@ -3,6 +3,7 @@
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+ = done, / = partial, - = todo, ordered by priority
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+ private key loading: der, without passphrase
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+ load all private keys from ipsec.d/private/ in stroke.c
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+ handle leftcert and rightcert in starterstroke.c/stroke.c
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@@ -28,7 +29,7 @@
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+ integrate basic PEM loading
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+ port x509 stuff
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- doxygen cleanup (charon/lib)
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+ doxygen cleanup (charon/lib)
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- implement 3DES to load encrypted pem files
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