X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=secnet.git;a=blobdiff_plain;f=README;h=ce3a4d70b44d4946462bf9f0c62718fd3a41463f;hp=b4f9a1563d21b6277056ed6bc1cb93fc3a00cce8;hb=359d8b326411f7e9c2418c094a130b0db14d859f;hpb=e7d6ffdaf26c91a05670954a3d84ed5fd9ea69b8 diff --git a/README b/README index b4f9a15..ce3a4d7 100644 --- a/README +++ b/README @@ -1,392 +1,598 @@ -subdirmk - assistance for non-recursive use of make -=================================================== - -Introduction ------------- - -Peter Miller's 1997 essay _Recursive Make Considered Harmful_ -persuasively argues that it is better to arrange to have a single -make invocation with the project's complete dependency tree, rather -than the currently conventional `$(MAKE) -C subdirectory' approach. - -However, actually writing a project's build system in a non-recursive -style is not very ergonomic. The main difficulties are: - - constantly having to write out long file and directory names - - the lack of a per-directory make variable namespace means - long make variables (or namespace clashes) - - it is difficult to arrange that one can cd to a subdirectory - and say `make all' and have something reasonable happen - (to wit, build an appropriate subset) - -`subdirmk' is an attempt to solve these problems (and it also slightly -alleviates some of the boilerplate needed to support out-of-tree -builds well). - -Basic approach --------------- +secnet - flexible VPN software -The developer is expected to write a makefile fragment, in each -relevant subdirectory, called `Subdir.sd.mk'. +* Copying -These fragments may contain ordinary make language. +secnet is + Copyright 1995-2003 Stephen Early + Copyright 2002-2014 Ian Jackson + Copyright 1991 Massachusetts Institute of Technology + Copyright 1998 Ross Anderson, Eli Biham, Lars Knudsen + Copyright 1993 Colin Plumb + Copyright 1998 James H. Brown, Steve Reid + Copyright 2000 Vincent Rijmen, Antoon Bosselaers, Paulo Barreto + Copyright 2001 Saul Kravitz + Copyright 2004 Fabrice Bellard + Copyright 2002 Guido Draheim + Copyright 2005-2010 Free Software Foundation, Inc. + Copyright 1995-2001 Jonathan Amery + Copyright 1995-2003 Peter Benie + Copyright 2011 Richard Kettlewell + Copyright 2012 Matthew Vernon + Copyright 2013-2019 Mark Wooding + Copyright 1995-2013 Simon Tatham -However, the sigil & is treated specially. By and large, it refers to -`the current directory'. There are a variety of convenient -constructions. +secnet is distributed under the terms of the GNU General Public +License, version 3 or later. Some individual files have more +permissive licences; where this is the case, it is documented in the +header comment for the files in question. + +secnet is distributed in the hope that it will be useful, but WITHOUT +ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +The file COPYING contains a copy of the GNU GPL v3. + + +* Introduction + +secnet allows large virtual private networks to be constructed +spanning multiple separate sites. It is designed for the case where a +private network connecting many hosts is 'hidden' behind a single +globally-routable IP address, but can also be applied in other +circumstances. It communicates entirely using UDP, and works well +with gateways that implement network address translation. + +If you are installing secnet to join an existing VPN, you should read +the 'INSTALL' file and your particular VPN's documentation now. You +may need to refer back to this file for information on the netlink and +comm sections of the configuration file. + +If you are thinking about setting up a new VPN of any size (from one +providing complete links between multiple sites to a simple +laptop-to-host link), read the section in this file on 'Creating a +VPN'. + +* Mailing lists and bug reporting + +There are two mailing lists associated with secnet: an 'announce' list +and a 'discuss' list. Their addresses are: +http://www.chiark.greenend.org.uk/mailman/listinfo/secnet-announce +http://www.chiark.greenend.org.uk/mailman/listinfo/secnet-discuss + +The -announce list receives one message per secnet release. The +-discuss list is for general discussion, including help with +configuration, bug reports, feature requests, etc. + +Bug reports should be sent to ; they will be +forwarded to the -discuss list by me. + +* Creating a VPN + +XXX TODO + +* secnet configuration file format + +By default secnet on linux reads /etc/secnet/secnet.conf. The default +may be different on other platforms. + +This file defines a dictionary (a mapping from keys to values) full of +configuration information for secnet. Two keys must be defined in +this file for secnet to start. One is "system", a dictionary +containing systemwide control parameters. The other is "sites", a +list of all the sites that you intend to communicate with. + +The configuration file has a very simple syntax; keys are defined as +follows: + +key definition; +or +key = definition; + +(the "=" is optional) + +Keys must match the following regular expression: +[[:alpha:]_][[:alnum:]\-_]* + +i.e. the first character must be an alpha or an underscore, and the +remaining characters may be alphanumeric, '-' or '_'. + +Keys can be defined to be a comma-separated list of any of the +following types: + + a boolean + a string, in quotes + a number, in decimal + a dictionary of definitions, enclosed in { } + a "closure", followed by arguments + a path to a key that already exists, to reference that definition + +Note that dictionaries can be nested: a key in one dictionary can +refer to another dictionary. When secnet looks for a key in a +particular directory and can't find it, it looks in the dictionary's +lexical 'parents' in turn until it finds it (or fails to find it at +all and stops with an error). -The result is that to a large extent, the Subdir.sd.mk has an easy way -to namespace its "local" make variables, and an easy way to refer to -its "local" filenames. +Definitions can refer to previous definitions by naming them with a +path. Paths are key1/key2/key3... (starting from wherever we find +key1, i.e. in the current dictionary or any of its parents), or +alternatively /key1/key2/key3... (to start from the root). +Definitions cannot refer to future definitions. -The Subdir.sd.mk's are filtered, fed through autoconf in the usual way -(for @..@-substitutions) and included by one autogenerated toplevel -makefile. +Example: -So all of the input is combined and passed to one make invocation. -(A corollary is that there is no enforcement of the namespacing: -discipline is required to prefix relevant variable names with &, etc.) +a=1; +b=2; +c={ d=3; e=a; }; +f={ a=4; g=c; }; -Each subdirectory is also provided with an autogenerated `Makefile' -which exists purely to capture ordinary make invocations and arrange -for something suitable to happen. - -Where there are dependencies between subdirectories, each Subdir.sd.mk -can simply refer to files in other subdirectories directly. - -Invocation, "recursive" per-directory targets ---------------------------------------------- - -Arrangements are made so that when you run `make foo' in a -subdirectory, it is like running the whole toplevel makefile, from the -toplevel, as `make subdir/foo'. If `subdir/foo' is a file that might -be built, that builds it. - -But `foo' can also be a conventional target like `all'. - -Each subdirectory has its own `all' target. For example a -subdirectory `src' has a target `src/all'. The rules for these are -automatically generated from the settings of the per-directory -&TARGETS variables. &TARGETS is magic in this way. (In -src/Subdir.sd.mk, &TARGETS of course refers to a make variable called -src_TARGETS.) - -The `all' target in a parent directory is taken to imply the `all' -targets in all of its subdirectories, recursively. And in the -autogenerated stub Makefiles, `all' is the default target. So if you -just type `make' in the toplevel, you are asking for `&all' -(/all) for every directory in the project. - -In a parallel build, the rules for all these various subdirectory -targets may be in run in parallel: there is only one `make' invocation -at a time. There is no sequencing between subdirectories, only been -individual targets (as specified according to their dependencies). - -You can define other per-directory recursive targets too: simply -mention (usually, by setting) the variable &TARGETS_zonk, or whatever. -This will create a src/zonk target (for appropriate value of src/). -Unlike `all', these other targets only exist in areas of the project -where at least something mentions them. So for example, if -&TARGETS_zonk is mentioned in src but not lib, `make zonk' in -lib will fail. If you want to make a target exist everywhere, -mention its name in Perdir.sd.mk (see below). - -Perdir.sd.mk, inclusion ------------------------ - -The file Perdir.sd.mk in the toplevel of the source is automatically -processed after each individual directory's Subdir.sd.mk, and the -&-substituted contents therefore appear once for each subdirectory. - -This lets you do per-directory boilerplate. Some useful boilerplate -is already provided in subdirmk, for you to reference like this: - &:include subdirmk/cdeps.sd.mk - &:include subdirmk/clean.sd.mk -For example you could put that in Perdir.sd.mk. - -Global definitions ------------------- - -If want to set global variables, such as CC, that should only be done -once. You can put them in your top-level Subdir.sd.mk, or a separate -file you `include' and declare using SUBDIRMK_MAKEFILES. - -If you need different settings of variables like CC for different -subdirectories, you should probably do that with target-specific -variable settings. See the info node `(make) Target-specific'. - -Subdirectory templates `.sd.mk' vs plain autoconf templates `.mk.in' --------------------------------------------------------------------- - -There are two kinds of template files. - - Filename .sd.mk .mk.in - - Processed by &-substitution, autoconf only - then autoconf - - Instantiated Usu. once per subdir Once only - - Need to be mentioned No, but Subdir.sd.mk All not in subdirmk/ - in configure.ac? via SUBDIRMK_SUBDIRS via SUBDIRMK_MAKEFILES - - How to include `&:include foo.sd.mk' `include foo.mk' - in all relevant .sd.mk in only one - (but not needed for Subdir.sd.mk - Subdir and Perdir) - -If you `include subdirmk/regen.mk', dependency management and -automatic regeneration for all of this template substitution, and for -config.status etc. is done for you. - -Summary of recommended directory reference syntaxes ---------------------------------------------------- - -Path construction &-expansions, meanings summary: - - Relative paths in... Absolute paths in... - build source build source - - This directory & &, &@ &@, - Top level . &; &@. &@; - -Adding `@' means "absolute path". (`&.' is not allowed without @ -because just `&./' is a silly way of writing `.'.) `/' terminates the -escape (needed if the next thing is not a lowercase character, or -space). `=' means "just the value, no /". Space starts multi-word -processing. - -In more detail, with the various options for what comes next: - - Recommended Relative paths in... Absolute paths in... - for build source build source - - This lc &file &,file &@file &@,file - directory any &/file &,/file &@/file &@,/file - several & f g h &, f g h &@ f g h &@, f g h - - Top lc file &;file &@.file &@;file - level any file &;/file &@./file &@;/file - several f g h &; f g h &@. f g h &@; f g h - .mk.in file $(src)/file $(abs)/file $(abs_src)/file - -Substitution syntax -------------------- - -In general & expands to the subdirectory name when used for a -filename, and to the subdirectory name with / replaced with _ for -variable names. - -Note that & is processed *even in makefile comments*. The substitutor -does not understand make syntax, or shell syntax, at all. However, -the substitution rules are chosen to work well with constructs which -are common in makefiles. - -In the notation below, we suppose that the substitution is being in -done in a subdirectory sub/dir of the source tree. In the RH column -we describe the expansion at the top level, which is often a special -case (in general in variable names we call that TOP rather than the -empty string). - -&CAPS => sub_dir_CAPS or TOP_CAPS -&lc => sub/dir/lc or lc - Here CAPS is any ASCII letter A-Z and lc is a-z. - The assumption is that filenames are usually lowercase and - variables usually uppercase. Otherwise, use another syntax: - -&_ => sub_dir_ or TOP_ -&=_ => sub_dir or TOP - -&/ => sub/dir/ or nothing -&=/ => sub/dir or . - -&,lc => $(top_srcdir)/sub/dir/lc &,/ => $(top_srcdir)/sub/dir/ -&;lc => $(top_srcdir)/lc &;/ => $(top_srcdir)/ - -&@lc => $(PWD)/sub/dir/lc &@/ => $(PWD)/sub/dir/ -&@.lc => $(PWD)/lc &@./ => $(PWD)/ -&@,lc => $(abs_top_srcdir)/sub/dir/lc &@,/ => $(abs_top_srcdir)/sub/dir/ -&@;lc => $(abs_top_srcdir)/lc &@;/ => $(abs_top_srcdir)/ - -In general: - = return subdir without delimiter (not allowed with `,' `;' `@') - , pathname of this subdirectory in source tree - ; pathname of top level of source tree - . pathname of this directory in build tree, `@' must be specified - @ absolute pathnames - -So pathname syntax is a subset of: - '&' [ '@' ] [ ',' | ';' | '.' ] [ lc | '/' ] - - To avoid incomprehensible .sd.mk files, some combinations are not - allowed. For example `&=./' would mean `.' and `&./' would be the - empty string. Variations with `=' and one of `@' `,' `;' are - uncommon and must be written using make variables instead. - -&& => && for convenience in shell runes -\& => & general escaping mechanism - -& thing thing... & &@ thing thing... & - &. thing thing... & -&, thing thing... & &@, thing thing... & -&; thing thing... & &@; thing thing... & - Convenience syntax for prefixing multiple filenames. - Introduced by & followed by lwsp where lc could go. - Each lwsp-separated non-ws word is prefixed by &/ etc. - etc. respectively. No other & escapes are recognised. - This processing continues until & preceded by lwsp, - or until EOL (the end of the line), or \ then EOL. - -&: .... - recognised at start of line only (possibly after lwsp) - args are processed for & - -&:include filename filename should usually be foo.sd.mk -&:-include filename tolerate nonexistent file - filenames are relative to $(top_srcdir) - -&! disables & until EOL (and then disappears) - -&# delete everything to end of line - (useful if the RHS contains unrecognised & constructions) - -&!STUFF - changes the escape sequence from & to literally STUFF - STUFF may be any series of of non-whitespace characters, - and is terminated by EOL or lwsp. &!STUFF and the lwsp - are discarded. - - After this, write STUFF instead of &, everywhere. - The effect is global and lasts until the next setting. - It takes effect on &:include'd files too, so maybe set - it back before using &:include. - - Notably - STUFFSTUFF => STUFFSTUFF - \STUFF => STUFF - STUFF!& set escape back to & - -&TARGETS_things - Handled specially. If mentioned, declares that this - subdir ought to have a target `things'. The rule will be - &/things:: $(&TARGETS_things) - - You may extend it by adding more :: rules for the target, - but the preferred style is to do things like this: - &TARGETS_check += & test-passed.stamp - - It is important to mention &TARGETS_things at least once in - the context of each applicable directory, because doing so - arranges that the *parent* will also have a `things' target - which recursively implies this directory's `things'. - - Must be spelled exactly &TARGETS_things. &_TARGETS_things, - for example, is not magic. But mentioning &TARGETS_things in - a #-comment *does* work because the & filter does not care - about comments. - - `all' is extra special: every directory has an `all' - target, which corresponds to &TARGETS. - -Subdirectory and variable naming --------------------------------- - -The simple variable decoration scheme does not enforce a strict -namespace distinction between parts of variable names which come from -subdirectory names, and parts that mean something else. - -So it is a good idea to be a bit careful with your directory naming. -`TOP', names that contain `_', and names that are similar to parts of -make variables (whether conventional ones, or ones used in your -project) are best avoided. - -If you name your variables in ALL CAPS and your subdirectories in -lower case with `-' rather than `_', there will be no confusion. - -Incorporating this into your project ------------------------------------- - -Use `git-subtree' to merge the subdirmk/ directory. You may find it -useful to symlink the DEVELOPER-CERTIFICATE file (git can store -symlinks as symlinks - just `git add' the link). And you probably -want to mention the situation in your top-level COPYING. - -Symlink autogen.sh into your project toplevel. - -In your configure.ac, say - - m4_include([subdirmk/subdirmk.ac]) - SUBDIRMK_SUBDIRS([...list of subdirectories in relative syntax...]) - -Write a Subdir.sd.mk in each directory. The toplevel one should -probably contain: - - include subdirmk/usual.mk - include subdirmk/regen.mk - -Write a Perdir.sd.mk in the toplevel, if you want. It should probably -have: - - &:include subdirmk/cdeps.sd.mk - &:include subdirmk/clean.sd.mk - -Hints ------ - -You can convert your project incrementally. Start with the top-level -Makefile.in and rename it to Subdir.sd.mk, and add the appropriate -stuff to configure.ac, and fix everything up. Leave the existing -$(MAKE) -C for your existing subdirectories alone. Then you can -convert individual subdirectories, or classes of subdirectories, at -your leisure. (You must be /sure/ that each subdirectory will be -entered only once at a time, but your existing recursive make descent -system should already do that or you already have concurrency bugs.) - -Aside from this, be very wary of any invocation of $(MAKE) anywhere. -This is a frequent source of concurrency bugs in recursive make build -systems. When combined with nonrecursive make it's all in the same -directory and there is nothing stopping the different invocations -ending up trying to make the same targets at the same time. That -causes hideous racy lossage. There are ways to get this to work -reliably but it is advanced stuff. - -If you make syntax errors, or certain kinds of other errors, in your -makefiles, you may find that just `make' is broken now and cannot get -far enough to regenerate a working set of makefiles. If this happens -just rerun ./config.status by hand. - - -Legal information ------------------ - -subdirmk is - Copyright 2019 Mark Wooding - Copyright 2019 Ian Jackson - - subdirmk and its example is free software; you can redistribute it - and/or modify it under the terms of the GNU Library General Public - License as published by the Free Software Foundation; either - version 2 of the License, or (at your option) any later version. - - This is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Library General Public License for more details. - - You should have received a copy of the GNU Library General Public - License along with this library as the file LGPL-2. - If not, see https://www.gnu.org/. - -Individual files generally contain the following tag in the copyright -notice, instead of the full licence grant text: - SPDX-License-Identifier: LGPL-2.0-or-later -As is conventional, this should be read as a licence grant. - -Contributions are accepted based on the git commit Signed-off-by -convention, by which the contributors' certify their contributions -according to the Developer Certificate of Origin version 1.1 - see -the file DEVELOPER-CERTIFICATE. - -Where subdirmk is used by and incorporated into another project (eg -via git subtree), the directory subdirmk/ is under GNU LGPL-2.0+, and -the rest of the project are under that other project's licence(s). -(The project's overall licence must be compatible with LGPL-2.0+.) +The following paths are valid: +a is 1 +b is 2 +c is a dictionary: + c/d is 3 + c/e is 1 +f is a dictionary: + f/a is 4 + f/g is a dictionary: + f/g/d is 3 + f/g/e is 1 + +Note that f/g/e is NOT 4. + +Elements that are lists are inserted into lists in definitions, not +referenced by them (i.e. you can't have lists of lists). + +Some closures may be followed by an argument list in ( ), and may +return any number of whatever type they like (including other +closures). Some types of closure (typically those returned from +invokations of other closures) cannot be invoked. + +closure { definitions } is short for closure({definitions}). + +The main body of secnet, and all the additional modules, predefine +some keys in the root dictionary. The main ones are: + + yes, true, True, TRUE, on: the boolean value True + no, false, False, FALSE, off: the boolean value False + makelist: turns a dictionary (arg1) into a list of definitions + (ignoring the keys) + readfile: reads a file (arg1) and returns it as a string + map: applies the closure specified as arg1 to each of the + remaining elements in the list in turn. Returns a list + made up of the outputs of the closure. + +Keys defined by modules are described below, in the module +documentation. + +Other configuration files can be included inline by writing "include +filename" at the start of a line. + +After the configuration file is read, secnet looks for particular keys +in configuration space to tell it what to do: + + system: a dictionary which can contain the following keys: + log (log closure): a destination for system messages + userid (string): the userid for secnet to run as once it drops privileges + pidfile (string): where to store its PID + + sites: a list of closures of type 'site', which define other tunnel + endpoints that secnet will attempt to communicate with + +* secnet command line options + +Usage: secnet [OPTION]... + + -f, --silent, --quiet suppress error messages + -w, --nowarnings suppress warnings + -v, --verbose output extra diagnostics + -c, --config=filename specify a configuration file + -j, --just-check-config stop after reading configfile + -n, --nodetach do not run in background + -d, --debug=item,... set debug options + --help display this help and exit + --version output version information and exit + +* secnet builtin modules + +** resolver + +Defines: + adns (closure => resolver closure) + +adns: dict argument + config (string): optional, a resolv.conf for ADNS to use + +** random + +Defines: + randomsrc (closure => randomsrc closure) + +randomsrc: string[,bool] + arg1: filename of random source + arg2: if True then source is blocking + +** udp + +Defines: + udp (closure => comm closure) + +udp: dict argument + address (string list): IPv6 or IPv4 addresses to listen and send on; + default is all local addresses + port (integer): UDP port to listen and send on; optional if you + don't need to have a stable address for your peers to talk to + (in which case your site ought probably to have `local-mobile true'). + buffer (buffer closure): buffer for incoming packets + authbind (string): optional, path to authbind-helper program + +** polypath + +Defines: + polypath (closure => comm closure) + +polypath: dict argument + port (integer): UDP port to listen and send on + buffer (buffer closure): buffer for incoming packets + authbind (string): optional, path to authbind-helper program + max-interfaces (number): optional, max number of different interfaces to + use (also, maximum steady-state amount of packet multiplication); + interfaces marked with `@' do not count. + interfaces (string list): which interfaces to process; each entry is + optionally `!' or `+' or `@' followed by a glob pattern (which is + applied to a prospective interface using fnmatch with no flags). + `+' or nothing means to process normally. `!' means to ignore; + `@' means to use only in conjunction with dedicated-interface-addr. + If no list is specified, or the list ends with a `!' entry, a + default list is used/appended: + "!tun*","!tap*","!sl*","!userv*","!lo","@hippo*","*". + Patterns which do not start with `*' or an alphanumeric need to be + preceded by `!' or `+' or `@'. + monitor-command (string list): Program to use to monitor appearance + and disappearance of addresses on local network interfaces. Should + produce lines of the form `+|- 4|6 ' where is + an address literal. Each - line should relate to a previously + printed + line. On startup, should produce a + line for each + currently existing address. secnet does filtering so there is no + need to strip out tun interfaces, multicast addresses, and so on. + The command is run as the user secnet is started as (not the one + which secnet may drop privilege to due to the configured `userid'). + The default depends on the operating system. + permit-loopback (boolean): Normally, loopback IPv6 and IPv4 + addresses on local interfaces are disregarded, because such + interfaces are not interesting for communicating with distant + hosts. Setting this option will ignore that check, which can be + useful for testing. Setting this option also removes "!lo*" from + the default interface pattern list. + +When using this comm, packets are sent out of every active interface +on the host (where possible). It is important that interfaces created +by secnet itself are not included! secnet's default filter list tries +to do this. + +This comm only makes sense for sites which are mobile. That is, the +site closures used with this comm should all have the `local-mobile' +parameter set to `true'. When the local site site is not marked +mobile the address selection machinery might fixate on an unsuitable +address. + +polypath takes site-specific informtion as passed to the `comm-info' +site closure parameter. The entries understood in the dictionary +are: + dedicated-interface-addr (string): IPv4 or IPv6 address + literal. Interfaces specified with `@' in `interfaces' will be + used for the corresponding site iff the interface local address + is this address. + +For an interface to work with polypath, it must either have a suitable +default route, or be a point-to-point interface. In the general case +this might mean that the host would have to have multiple default +routes. However in practice the most useful configuration is two +interfaces being (1) wifi (2) mobile internet. + +I have had success on Linux by using network-manager for wifi and +invoking ppp directly for mobile internet. ppp sets up a +point-to-point link, and does not add a default route if there already +is one. network-manager always sets up a default route. The result +is that the wifi always has a default route (so is useable); ppp +(being a point-to-point link) does not need one. + +The use of polypath requires that secnet be started with root +privilege, to make the setsockopt(,,SO_BINDTODEVICE,) calls. If the +configuration specifies that secnet should drop privilege (see +`userid' above), secnet will keep a special process around for this +purpose; that process will handle local network interface changes but +does not deal with any packets, key exchange, etc. + +polypath support is only available when secnet is built against an +IPv6-capable version of adns (because it wants features in the newer +adns). + +** log + +Defines: + logfile (closure => log closure) + syslog (closure => log closure) + +logfile: dict argument + filename (string): where to log to + class (string list): what type of messages to log + { "debug-config", M_DEBUG_CONFIG }, + { "debug-phase", M_DEBUG_PHASE }, + { "debug", M_DEBUG }, + { "all-debug", M_DEBUG|M_DEBUG_PHASE|M_DEBUG_CONFIG }, + { "info", M_INFO }, + { "notice", M_NOTICE }, + { "warning", M_WARNING }, + { "error", M_ERROR }, + { "security", M_SECURITY }, + { "fatal", M_FATAL }, + { "default", M_WARNING|M_ERROR|M_SECURITY|M_FATAL }, + { "verbose", M_INFO|M_NOTICE|M_WARNING|M_ERROR|M_SECURITY|M_FATAL }, + { "quiet", M_FATAL } + +logfile will close and reopen its file upon receipt of SIGHUP. + +syslog: dict argument + ident (string): include this string in every log message + facility (string): facility to log as + { "authpriv", LOG_AUTHPRIV }, + { "cron", LOG_CRON }, + { "daemon", LOG_DAEMON }, + { "kern", LOG_KERN }, + { "local0", LOG_LOCAL0 }, + { "local1", LOG_LOCAL1 }, + { "local2", LOG_LOCAL2 }, + { "local3", LOG_LOCAL3 }, + { "local4", LOG_LOCAL4 }, + { "local5", LOG_LOCAL5 }, + { "local6", LOG_LOCAL6 }, + { "local7", LOG_LOCAL7 }, + { "lpr", LOG_LPR }, + { "mail", LOG_MAIL }, + { "news", LOG_NEWS }, + { "syslog", LOG_SYSLOG }, + { "user", LOG_USER }, + { "uucp", LOG_UUCP } + +** util + +Defines: + sysbuffer (closure => buffer closure) + +sysbuffer: integer[,dict] + arg1: buffer length + arg2: options: + lockdown (boolean): if True, mlock() the buffer + +** site + +Defines: + site (closure => site closure) + +site: dict argument + local-name (string): this site's name for itself + name (string): the name of the site's peer + link (netlink closure) + comm (one or more comm closures): if there is more than one, the + first one will be used for any key setups initiated by us using the + configured address. Others are only used if our peer talks to + them. + resolver (resolver closure) + random (randomsrc closure) + local-key (rsaprivkey closure) + address (string list): optional, DNS name(s) used to find our peer; + address literals are supported too if enclosed in `[' `]'. + port (integer): mandatory if 'address' is specified: the port used + to contact our peer + key (rsapubkey closure): our peer's public key + transform (transform closure): how to mangle packets sent between sites + dh (dh closure) + hash (hash closure) + key-lifetime (integer): max lifetime of a session key, in ms + [one hour; mobile: 2 days] + setup-retries (integer): max number of times to transmit a key negotiation + packet [5; mobile: 30] + setup-timeout (integer): time between retransmissions of key negotiation + packets, in ms [2000; mobile: 1000] + wait-time (integer): after failed key setup, wait roughly this long + (in ms) before allowing another attempt [20000; mobile: 10000] + Actual wait time is randomly chosen between ~0.5x and ~1.5x this. + renegotiate-time (integer): if we see traffic on the link after this time + then renegotiate another session key immediately (in ms) + [half key-lifetime, or key-lifetime minus 5 mins (mobile: 12 hours), + whichever is longer]. + keepalive (bool): if True then attempt always to keep a valid session key. + [false] + log-events (string list): types of events to log for this site + unexpected: unexpected key setup packets (may be late retransmissions) + setup-init: start of attempt to setup a session key + setup-timeout: failure of attempt to setup a session key, through timeout + activate-key: activation of a new session key + timeout-key: deletion of current session key through age + security: anything potentially suspicious + state-change: steps in the key setup protocol + packet-drop: whenever we throw away an outgoing packet + dump-packets: every key setup packet we see + errors: failure of name resolution, internal errors + peer-addrs: changes to sets of peer addresses (interesting for mobile peers) + all: everything (too much!) + mobile (bool): if True then peer is "mobile" ie we assume it may + change its apparent IP address and port number without either it + or us being aware of the change; so, we remember the last several + port/addr pairs we've seen and send packets to all of them + (subject to a timeout). We maintain one set of addresses for key + setup exchanges, and another for data traffic. Two communicating + peers must not each regard the other as mobile, or all the traffic + in each direction will be triplicated (strictly, transmitted + mobile-peers-max times) and anyway two peers whose public contact + address may suddenly change couldn't communicate reliably because + their contact addresses might both change at once. [false] + mobile-peers-max (integer): Maximum number of peer port/addr pairs we + remember and send to. Must be at least 1 and no more than 5. + [4 if any address is configured, otherwise 3] + static-peers-max (integer): Maximum number of peer port/addr pairs + we can try for a static site. Must be at least 1 and no more + than 5. [4 or 3, as above] + mobile-peer-expiry (integer): For "mobile" peers only, the length + of time (in seconds) for which we will keep sending to multiple + address/ports from which we have not seen incoming traffic. [120] + local-mobile (bool): if True then other peers have been told we are + "mobile". This should be True iff the peers' site configurations + for us have "mobile True" (and if we find a site configuration for + ourselves in the config, we insist on this). The effect is to + check that there are no links both ends of which are allegedly + mobile (which is not supported, so those links are ignored) and + to change some of the tuning parameter defaults. [false] + mtu-target (integer): Desired value of the inter-site MTU for this + peering. This value will be advertised to the peer (which ought + to affect incoming packets), and if the peer advertises an MTU its + value will be combined with this setting to compute the inter-site + MTU. (secnet will still accept packets which exceed the + (negotiated or assumed) inter-site MTU.) Setting a lower + inter-site MTU can be used to try to restrict the sizes of the + packets sent over the underlying public network (e.g. to work + around network braindamage). It is not normally useful to set a + larger value for mtu-target than the VPN's general MTU (which + should be reflected in the local private interface MTU, ie the mtu + parameter to netlink). If this parameter is not set, or is set + to 0, the default is to use the local private link mtu. + comm-info (dict): Information for the comm, used when this site + wants to transmit. If the comm does not support this, it is + ignored. + +Links involving mobile peers have some different tuning parameter +default values, which are generally more aggressive about retrying key +setup but more relaxed about using old keys. These are noted with +"mobile:", above, and apply whether the mobile peer is local or +remote. + +** transform-eax + +Defines: + eax-serpent (closure => transform closure) + +** transform-cbcmac + +Defines: + serpent256-cbc (closure => transform closure) + +** netlink + +Defines: + null-netlink (closure => closure or netlink closure) + +null-netlink: dict argument + name (string): name for netlink device, used in log messages + networks (string list): networks on the host side of the netlink device + remote-networks (string list): networks that may be claimed + by the remote site using this netlink device + local-address (string): IP address of host's tunnel interface + secnet-address (string): IP address of this netlink device + ptp-address (string): IP address of the other end of a point-to-point link + mtu (integer): MTU of host's tunnel interface + +Only one of secnet-address or ptp-address may be specified. If +point-to-point mode is in use then the "routes" option must also be +specified, and netlink returns a netlink closure that should be used +directly with the "link" option to the site closure. If +point-to-point mode is not in use then netlink returns a closure that +may be invoked using a dict argument with the following keys to yield +a netlink closure: + routes (string list): networks reachable down the tunnel attached to + this instance of netlink + options (string list): + allow-route: allow packets coming from this tunnel to be routed to + other tunnels as well as the host (used for mobile devices like laptops) + soft: remove these routes from the host's routing table when + the tunnel link quality is zero + mtu (integer): MTU of host's tunnel interface + +Netlink will dump its current routing table to the system/log on +receipt of SIGUSR1. + +** slip + +Defines: + userv-ipif (closure => netlink closure) + +userv-ipif: dict argument + userv-path (string): optional, where to find userv ["userv"] + service-user (string): optional, username for userv-ipif service ["root"] + service-name (string): optional, name of userv-ipif service ["ipif"] + buffer (buffer closure): buffer for assembly of host->secnet packets + plus generic netlink options, as for 'null-netlink' + +** tun + +Defines: + tun (closure => netlink closure) [only on linux-2.4] + tun-old (closure => netlink closure) + +tun: dict argument + flavour (string): optional, type of TUN interface to use + ("guess","linux","bsd","streams") + device (string): optional, path of TUN/TAP device file ["/dev/net/tun"] + interface (string): optional, name of tunnel network interface + ifconfig-path (string): optional, path to ifconfig command + route-path (string): optional, path to route command + ifconfig-type (string): optional, how to perform ifconfig + route-type (string): optional, how to add and remove routes + types are: "guess", "ioctl", "bsd", "linux", "solaris-2.5" + buffer (buffer closure): buffer for host->secnet packets + plus generic netlink options, as for 'null-netlink' + +I recommend you don't specify the 'interface' option unless you're +doing something that requires the interface name to be constant. + +** rsa + +Defines: + rsa-private (closure => rsaprivkey closure) + rsa-public (closure => rsapubkey closure) + +rsa-private: string[,bool] + arg1: filename of SSH private key file (version 1, no password) + arg2: whether to check that the key is usable [default True] + +rsa-public: string,string + arg1: encryption key (decimal) + arg2: modulus (decimal) + +** dh + +Defines: + diffie-hellman (closure => dh closure) + +diffie-hellman: string,string[,bool] + arg1: modulus (hex) + arg2: generator (hex) + arg3: whether to check that the modulus is prime [default True] + +** md5 + +Defines: + md5 (hash closure) + +** sha1 + +Defines: + sha1 (hash closure) + +** conffile + +Defines: + makelist (dictionary => list of definitions) + readfile (string => string) + map (closure,list => list) + +makelist: dictionary + returns a list consisting of the definitions in the dictionary. The keys + are discarded. + +readfile: string + reads the named file and returns its contents as a string + +map: + applies the closure specified as arg1 to each of the elements in the list. + Returns a list made up of the outputs of the closure.