4 secnet \- VPN router daemon
7 \fBsecnet\fR [\fIOPTIONS\fR]
10 \fBsecnet\fR allows virtual private networks to be constructed
11 spanning multiple separate sites.
15 .B --verbose\fR, \fB-v
16 Enable extra diagnostics.
18 .B --nowarnings\fR, \fB-w
22 Display usage message.
25 Display version string.
27 .B --nodetach\fR, \fB-n
28 Don't go into background.
29 The default behaviour is to become a daemon during startup.
31 .B --silent\fR, \fB--quiet\fR, \fB-f
32 Suppress error messages.
35 Enable debug messages.
37 .B --config\fR, \fB-c \fIPATH
38 Specify configuration file.
39 The default is \fI/etc/secnet/secnet.conf\fR.
41 .B --just-check-config\fR, \fB-j
42 Check configuration and exit.
44 .B --sites-key\fR, \fB-s \fIKEY
45 Configuration file key defining active sites.
46 The default is \fBsites\fR.
48 .SH "CONFIGURATION FILE"
50 The default configuration file is \fI/etc/secnet/secnet.conf\fR.
51 This can be overridden with the \fB--config\fR option.
53 The configuration file defines a dictionary (a mapping from keys to
54 values) of configuration information for secnet.
55 It is recursive in nature, i.e. values may themselves include dictionaries.
56 Any node in the nested structure thus defined can be identified by a
57 \fIpath\fR, which is the sequence of keys necessary to reach it from
58 the root, separated by "/" characters.
59 See \fBPaths\fR below for how this is used.
61 Furthermore, when a key is looked up in a dictionary, if it cannot be
62 found, it is sought in the parent dictionary, and so on back to the
64 For instance, each \fIsite\fR must contain the \fBresolver\fR key, but
65 in a typical configuration there is no value in having different
66 resolvers for each site.
67 Therefore \fBresolver\fR is defined at the root and thus automatically
68 incorporated into all sites.
70 Whitespace, including newlines, is ignored except to the extent that
71 it bounds other symbols.
73 Comment begin with "#" and continues to the end of the line.
76 A file may be recursively included into the configuration file using a
81 This is handled at a higher level than the main parser and so
82 precludes the possibility of using the string \fBinclude\fR for any
84 .\" check if this is true. it's probably a bug!
86 The configuration file contains one or more assigments.
87 Each assignment is written:
89 \fIkey\fR [\fB=\fR] \fIlist\fR\fB;\fR
91 i.e. the equals sign is optional.
92 The semicolon is mandatory in all contexts.
94 Keys start with a letter or "_" and continue with any numbers of
95 letters, digits, "_" and "-".
97 Each \fIkey\fR is a list of one or more \fIvalues\fR, separated by commas.
98 Possible values types are \fIboolean\fR, \fIstring\fR, \fInumber\fR,
99 \fIdictionary\fR, \fIpath\fR and \fIclosure evaluation\fR.
100 .\" This man page draws a distinction between a closure (the thing
101 .\" evaluated) and a closure evaluation (the closure plus is
104 Strings are contained within "double quotes".
105 There is (currently) no escape syntax and no way to include quotes
110 filename "/var/log/secnet";
113 Numbers are encoded in decimal and do not include a sign.
114 Numbers must lie in the range 0 to 4294967295.
121 .\" In conffile.y dictionaries can be preceded by a search path, but
122 .\" this is not implemented elsewhere, so not documented here.
123 Dictionaries consist of one or more assignments, in the same syntax as
124 given above, enclosed in "{" and "}".
130 pidfile "/var/run/secnet.pid";
134 Paths allow a key already defined in the configuration to be aliased.
136 Paths consist of a sequence of keys separated by "/".
137 If the path starts with a "/" then it is an \fIabsolute path\fR and
138 the search starts at the root of the configuration.
139 Otherwise it is a \fIrelative path\fR and starts in the containing
140 dictionary or in any of its parents, down to and including the root.
141 If there is more than one match, the one furthest from the root "wins".
143 The value of a path is the list assigned to the key it refers to.
144 Lists are flattened; for example if a key is defined as a list of two
145 paths, and each of those refers to a list of two integers, the
146 original key is therefore defined to be a list of four integers, not
147 a list consisting of two lists.
149 It is not possible to refer to a \fIlater\fR key using a path.
155 kakajou vpn-data/test/kakajou/kakajou;
156 araminta vpn-data/test/araminta/araminta;
157 deodand vpn-data/test/deodand/deodand;
158 all-sites kakajou,araminta,deodand;
161 all-sites vpn/test/all-sites;
164 Here, each of \fBvpn/test/kakajou\fR, \fBvpn/test/araminta\fR and
165 \fBvpn/test/deodand\fR are defined as aliases to values defined
167 \fBvpn/tests/all-sites\fR is defined as the list of all three of those
168 values, and \fBall-sites\fR is then defined to be an alias for that.
170 The (single-element) paths \fBfalse\fR, \fBno\fR and \fBnowise\fR are
171 predefined and refer to a boolean false value.
172 Similarly \fBtrue\fR, \fByes\fR and \fBverily\fR point at a boolean
175 In all six cases, variants with just the first letter capitalized, and
176 with all letters capitalized, are also provided.
180 random randomfile("/dev/urandom",no);
182 .SS "Closure Evaluation"
183 Closure evaluation uses the following syntax:
185 \fICLOSURE \fB( \fIARGUMENTS \fB)
187 \fICLOSURE\fR may be a path referring to a closure, or may itself be a
190 \fIARGUMENTS\fR is a list of zero or more values, separated by commas.
191 As a shortcut, if the arguments consist of a single dictionary, the
192 parentheses may be ommitted:
194 \fICLOSURE \fB{ \fR... \fB}
198 sites map(site, vpn/test/all-sites);
201 When a closure is evaluated it returns a value (a list, much as above)
202 and may also have side effects (which may be immediate or may be
203 deferred to some later phase of execution).
204 A list of built-in closures is given below.
206 Two keys are mandatory.
207 \fBsystem\fR must be a dictionary in which the following keys can be
211 A \fIlog closure\fR; see the \fBlogfile\fR documentation below.
212 The destination for log messages.
217 The userid to run as after dropping privilege.
222 The path to write a pidfile.
225 \fBsites\fR should be a list of \fIsite closures\fR; see the \fBsite\fR documentation below.
226 This defines the collection of tunnel endpoints that \fBsecnet\fR will
229 Recall the recursive lookup logic described in \fBOverview\fR above:
230 if (for instance) \fBlog\fR is defined in the top level dictionary but
231 not in \fBsystem\fR, it will nevertheless be found when looked up in
235 \fBsecnet\fR contains a collection of built-in closures
236 with names (i.e. single-element paths) given below.
238 Most of them return anonymous closures of various types,
239 which are described contextually.
242 \fBadns(\fIDICT\fB)\fR => \fIresolver closure\fR
245 This either be empty or contain the single key \fBconfig\fR, with a
246 string value giving configuration to supply to ADNS.
247 This might be read from a file using \fBreadfile\fR.
249 A \fIresolver closure\fR is a means of converting hostnames into
254 \fBdiffie-hellman(\fIMODULUS\fB, \fIGENERATOR\fR[\fB, \fICHECK\fR]\fB)\fR => \fIdh closure\fR
258 The prime modulus \fIp\fR in hex.
262 The generator \fIg\fR in hex.
266 If \fBtrue\fR (the default) then check if \fIp\fR is prime.
268 A \fIdh closure\fR defines a group to be used for key exchange.
269 The same group must be used by all sites in the VPN.
272 \fBlogfile(\fIDICT\fB)\fR => \fIlog closure\fR
274 Valid keys in the \fIDICT\fR argument are:
280 A list of strings defining which classes of message to log.
281 The possible message classes are \fBdebug-config\fR,
282 \fBdebug-phase\fR, \fBdebug\fR, \fBinfo\fR, \fBnotice\fR,
283 \fBwarning\fR, \fBerror\fR, \fBsecurity\fR and \fBfatal\fR.
285 \fBall-debug\fR is the union of all the \fBdebug\fR... classes.
286 \fBdefault\fR is equivalent to \fBwarning, error, security, fatal\fR.
287 \fBverbose\fR is equivalent to \fBinfo, notice, warning, error,
289 \fBquiet\fR is equivalent to \fBfatal\fR.
291 A \fIlog closure\fR is a means of saving log messages.
292 See also \fBsyslog\fR below.
295 \fBmakelist(\fIDICT\fB)\fR => \fILIST\fR
297 Returns the (flattened) list of values from the dictionary, discarding
301 \fBmap(\fICLOSURE\fB, \fIINPUT\fR...\fB)\fR => \fILIST\fR
303 Applies \fICLOSURE\fR to all its additional input arguments and
304 returns the resulting list.
307 \fBmd5\fR is a \fIhash closure\fR implementing the MD5 algorithm.
310 \fBnull-netlink(\fIDICT\fB)\fR => \fInetlink closure\fR
312 \fBnull-netlink(\fIDICT\fB)\fR => \fIpure closure\fR
313 .\" TODO pure closure is what it's called internally but this is a
314 .\" very opaque name to use in docs
316 Valid keys in the \fIDICT\fR argument are:
320 The name for the netlink device.
321 The default is \fBnull-netlink\fR.
325 The networks on the host side of the netlink device.
329 Networks that may be claimed by remote sites using this netlink device.
333 IP address of this netlink.
334 Incompatible with \fBptp-address\fR.
338 IP address of the other end of a point-to-point link.
339 Incompatible with \fBsecnet-address\fR.
343 The MTU of the netlink device.
346 If \fBptp-address\fR is used then the result is a \fInetlink closure\fR.
347 This can be used directly with the \fBlink\fR key in the \fBsites\fR
350 If \fBsecnet-address\fR is used then the result is a \fIpure
352 This must be evaluated to yield a \fInetlink closure\fR, using a
353 dictionary argument with the following keys:
357 networks reachable via this tunnel, in \fIaddress\fB/\fIbits\fR format.
365 Allow packets received via this tunnel to be routed down other tunnels
366 (without this option only packets from the host will be routed).
369 Remove these routes from the host routing table when the link quality
375 Default MTU over this link.
376 The default is inherited from the \fIpure closure\fR.
380 The priority of this link.
381 Higher values beat lower values.
384 .\" TODO ptp-address turns up in sites.conf, but why? I think this
385 .\" is a bug in make-secnet-sites; it is not used by
386 \" netlink_inst_create.
389 A \fInetlink closure\fR is a virtual IP link, and is supplied to the
390 \fBlink\fR key of a \fIsite\fR closure.
392 The netlink created by \fBnull-netlink\fR has no connection to the
394 See \fBtun\fR and \fBuserv-ipif\fR below for more useful alternatives.
399 \fBrandomfile(\fIFILENAME\fR[\fB, \fIBLOCKING\fR]\fB)\fR => \fIrandomsource closure\fR
403 Path to random device, e.g. \fI/dev/urandom\fR.
407 \fBTrue\fR if this is a blocking device and \fBfalse\fR otherwise (the default).
408 Blocking device support is not implemented so this must always be
409 \fBFalse\fR or absent.
411 A \fIrandomsource closure\fR is a source of random numbers.
414 \fBreadfile(\fIPATH\fB)\fR => \fISTRING\fR
416 Read the contents of the file \fIPATH\fR (a string) and return it as a string.
419 \fBserpent256-cbc(\fIDICT\fB)\fR => \fItransform closure\fR
421 Valid keys in the \fIDICT\fR argument are:
424 The maximum acceptable difference between the sequence number in a
425 received, decrypted message and the previous one.
427 It may be necessary to increase this is if connectivity is poor.
429 A \fItransform closure\fR is a reversible means of transforming
430 messages for transmission over a (presumably) insecure network.
431 It is responsible for both confidentiality and integrity.
434 \fBrsa-private(\fIPATH\fB\fR[, \fICHECK\fR]\fB)\fR => \fIrsaprivkey closure\fR
438 The path to a file containing an RSA private key in SSH format
440 There must be no passphrase.
444 If \fBtrue\fR (the default) then check that the key is valid.
447 \fBrsa-public(\fIKEY\fB, \fIMODULUS\fB)\fR => \fIrsapubkey closure\fR
451 The public key exponent (\fIe\fR), in decimal.
455 The modulus (\fIn\fR), in decimal.
458 \fBsha1\fR is a \fIhash closure\fR implementing the SHA-1 algorithm.
461 \fBsite(\fIDICT\fB)\fR => \fIsite closure\fR
463 Valid keys in the \fIDICT\fR argument are:
467 The site's name for itself.
471 The name of the site's peer.
474 A \fInetlink closure\fR.
477 A \fIcomm closure\fR.
480 A \fIresolver closure\fR.
483 A \fIrandomsource closure\fR.
486 An \fIrsaprivkey closure\fR.
487 The key used to prove our identity to the peer.
491 The DNS name of the peer.
492 Optional, but if it is missing then it will not be possible to
493 initiate new connections to the peer.
497 The port to contact the peer.
500 An \fIrsapubkey closure\fR.
501 The key used to verify the peer's identity.
504 A \fItransform closure\fR.
505 Used to protect packets exchanged with the peer.
509 The group to use in key exchange.
512 The hash function used during setup.
513 .\" TODO clarify what we actually use it for!
517 The maximum lifetime of a session key in milliseconds.
518 The default is one hour.
522 The maximum number of times a key negotiation packet will be
523 transmitted before giving up.
528 The time between retransmissions of key negotiation packets, in milliseconds.
529 The default is one second.
533 The time to wait after a failed key setup before making another
534 attempt, in milliseconds.
539 The time after which a new session key will be negotiated, \fIif\fR
540 there is traffic on the link, in milliseconds.
541 It must not be greater than the \fBkey-lifetime\fR.
542 The default 5 minutes less than the key lifetime, unless the lifetime
543 is less than 10 minutes in which case the default is half the
548 If \fBtrue\fR then attempt to always maintain a live session key.
553 Types of event to log for this site.
557 Unexpected key setup packets (including late retransmissions).
560 Start of attempt to setup a session key.
563 Failure of attempt to setup a session key, through timeout.
566 Activation of a new session key.
569 Deletion of current session key through age.
572 Anything potentially suspicious.
575 Steps in the key setup protocol.
578 Whenever we throw away an outgoing packet.
581 Every key setup packet we see.
584 Failure of name resolution, internal errors.
587 Everything (too much!)
590 A \fIsite closure\fR defines one site to communicate with.
591 \fBsecnet\fR expects the (root) key \fBsite\fR to be a list of site
595 \fBsysbuffer(\fR[\fISIZE\fR[\fB, \fIOPTIONS\fR]]\fB)\fR => \fIbuffer closure\fR
599 The size of the buffer in bytes.
600 This must be between 64 and 131072.
605 Optional and presently unused.
606 .\" lockdown is accepted but ignored.
608 A \fIbuffer closure\fR is a means of buffering packets to send or that
612 \fBsyslog(\fIDICT\fB)\fR => \fIlog closure\fR
614 Valid keys in the \fIDICT\fR argument are:
618 The ident string to pass to \fBopenlog\fR(3); this value will appear
623 The facility to log as.
624 The possible values are \fBauthpriv\fR, \fBcron\fR, \fBdaemon\fR,
625 \fBkern\fR, \fBlocal0\fR-\fB7\fR, \fBlpr\fR, \fBmail\fR, \fBnews\fR,
626 \fBsyslog\fR, \fBuser\fR and \fBuucp\fR.
628 See also \fBlogfile\fR above.
631 \fBtun(\fIDICT\fB)\fR => \fInetlink closure\fR
633 \fBtun(\fIDICT\fB)\fR => \fIpure closure\fR
635 Valid keys in the \fIDICT\fR argument are those documented for
636 \fBnull-netlink\fR above, plus:
640 The type of TUN interface to use.
641 Possible values are \fBlinux\fR, \fBbsd\fR, \fBstreams\fR and \fBguess\fR.
642 The default is \fBguess\fR.
646 The path to the TUN/TAP device file.
647 The default is \fI/dev/net/tun\fR for the \fBlinux\fR flavour and
648 \fI/dev/tun\fR for the others.
652 The interface to use.
653 The default is to pick one automatically.
654 This cannot be used with the \fBstreams\fR flavour.
658 IP address of the host's tunnel interface.
659 .\" README says this belongs to netlink-null but actually it's
660 \" duplicated between slip & tun
664 The name of the \fBifconfig\fR command.
665 The default is simply "ifconfig".
669 The name of the \fBroute\fR command.
670 The default is simply "route".
674 The syntax expected by the \fBifconfig\fR command.
675 Possible values are \fBlinux\fR, \fBbsd\fR, \fBioctl\fR,
676 \fBsolaris-2.5\fR and \fBguess\fR.
677 The default is \fBguess\fR.
681 The syntax expected by the \fBifconfig\fR command.
682 Possible values are \fBlinux\fR, \fBbsd\fR, \fBioctl\fR,
683 \fBsolaris-2.5\fR and \fBguess\fR.
684 The default is \fBguess\fR.
687 A \fIbuffer closure\fR to use for packets transferred from the host to secnet.
688 The buffer size must be at least 60 greater than the MTU.
689 .\" TODO rumour has is that buffers are sometimes shareable between
690 .\" netlink devices - document that if the conditions are reasonable
693 The \fBifconfig-type\fR and \fBroute-type\fR values determine how
694 those commands are executed.
695 If they are set to \fBioctl\fR then low-level system calls are used
696 directly instead of invoking the commands.
698 The netlink created by \fBtun\fR uses the \fBtun\fR device to
699 communicate with the host kernel.
702 \fBudp(\fIDICT\fB)\fR => \fIcomm closure\fR
704 Valid keys in the \fIDICT\fR argument are:
708 The IP address to bind on.
709 The default is 0.0.0.0, i.e. "any".
713 The port number to bind to.
714 The default is 0, i.e. the OS will choose one.
715 It is suggested that any given VPN agree a common port number.
718 A \fIbuffer closure\fR.
719 See the \fBsysbuffer\fR closure above.
723 The path to a helper program to bind the socket.
726 The program will be invoked with the address and port number as its
727 arguments, and with the socket to bind as file descriptor 0.
728 It should either bind the socket as requested, or exit with nonzero
731 A \fIcomm closure\fR is a means of sending and receiving messages via
733 It does not provide confidentiality, reliablity or availability.
736 \fBuserv-ipif(\fIDICT\fB)\fR => \fInetlink closure\fR
738 \fBuserv-ipif(\fIDICT\fB)\fR => \fIpure closure\fR
740 Valid keys in the \fIDICT\fR argument are those documented for
741 \fBnull-netlink\fR above, plus:
745 IP address of the host's SLIP interface.
746 .\" README says this belongs to netlink-null but actually it's
747 \" duplicated between SLIP & tun
751 Where to find \fBuserv\fR(1).
752 The default is \fB"userv"\fR.
756 The name of the user that owns the service.
757 The default is \fB"root"\fR.
761 The name of the service to request.
762 The default is \fB"ipif"\fR.
765 A \fIbuffer closure\fR to use for packets transferred from the host to secnet.
767 The netlink created by \fBuserv-ipif\fR invokes the specified \fBuserv\fR service with pipes connected to its standard input and output.
768 It uses SLIP to communicate with the host kernel via these pipes.
772 .I /etc/secnet/secnet.conf