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Revision 1.7 by pcg, Sun Mar 6 22:45:29 2005 UTC vs.
Revision 1.29 by root, Tue Dec 4 10:29:43 2012 UTC

2 2
3gvpe.conf - configuration file for the GNU VPE daemon 3gvpe.conf - configuration file for the GNU VPE daemon
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 # global options for all nodes
7 udp-port = 407 8 udp-port = 407
8 mtu = 1492 9 mtu = 1492
9 ifname = vpn0 10 ifname = vpn0
10 11
12 # first node is named branch1 and is at 1.2.3.4
11 node = branch1 13 node = branch1
12 hostname = 1.2.3.4 14 hostname = 1.2.3.4
13 15
16 # second node uses dns to resolve the address
14 node = branch2 17 node = branch2
15 hostname = www.example.net 18 hostname = www.example.net
16 udp-port = 500 # this host uses a different udp-port 19 udp-port = 500 # this host uses a different udp-port
17 20
21 # third node has no fixed ip address
18 node = branch3 22 node = branch3
19 connect = ondemand 23 connect = ondemand
20 24
21=head1 DESCRIPTION 25=head1 DESCRIPTION
22 26
23The gvpe config file consists of a series of lines that contain C<variable 27The gvpe config file consists of a series of lines that contain C<variable
24= value> pairs. Empty lines are ignored. Comments start with a C<#> and 28= value> pairs. Empty lines are ignored. Comments start with a C<#> and
25extend to the end of the line. They can be used on their own lines, or 29extend to the end of the line. They can be used on their own lines, or
26after any directives. Spaces are allowed before or after the C<=> sign or 30after any directives. Whitespace is allowed around the C<=> sign or after
27after values, but not within the variable names or values themselves. 31values, but not within the variable names or values themselves.
28 32
29The only exception to the above is the "on" directive that can prefix any 33All settings are applied "in order", that is, later settings of the same
30C<name = value> setting and will only "execute" it on the named node, or 34variable overwrite earlier ones.
31(if the nodename starts with "!") on all nodes except the named one.
32 35
33 name = value 36The only exceptions to the above are the "on" and "include" directives:
37
38=over 4
39
40=item on nodename ...
41
42=item on !nodename ...
43
44You can prefix any configuration directive with C<on> and a nodename. GVPE
45will will only "execute" it on the named node, or (if the nodename starts
46with C<!>) on all nodes except the named one.
47
48Example: set the MTU to C<1450> everywhere, C<loglevel> to C<noise> on
49C<branch1>, and C<connect> to C<ondemand> everywhere but on branch2.
50
51 mtu = 1450
34 on branch1 loglevel = noise 52 on branch1 loglevel = noise
35 on !branch2 connect = ondemand 53 on !branch2 connect = ondemand
36 54
37All settings are executed "in order", that is, later settings of the same 55=item include relative-or-absolute-path
38variable overwrite earlier ones. 56
57Reads the specified file (the path must not contain whitespace or C<=>
58characters) and evaluate all config directives in it as if they were
59spelled out in place of the C<include> directive.
60
61The path is a printf format string, that is, you must escape any C<%>
62by doubling it, and you can have a single C<%s> inside, which will be
63replaced by the current nodename.
64
65Relative paths are interpreted relative to the GVPE config directory.
66
67Example: include the file F<local.conf> in the config directory on every
68node.
69
70 include local.conf
71
72Example: include a file F<conf/>nodenameF<.conf>
73
74 include conf/%s.conf
75
76=back
39 77
40=head1 ANATOMY OF A CONFIG FILE 78=head1 ANATOMY OF A CONFIG FILE
41 79
42Usually, a config file starts with global settings (like the udp port to 80Usually, a config file starts with a few global settings (like the UDP
43listen on), followed by node-specific sections that begin with a C<node = 81port to listen on), followed by node-specific sections that begin with a
44nickname> line. 82C<node = nickname> line.
45 83
46Every node that is part of the network must have a section that starts 84Every node that is part of the network must have a section that starts
47with C<node = nickname>. The number and order of the nodes is important 85with C<node = nickname>. The number and order of the nodes is important
48and must be the same on all hosts. It is not uncommon for node sections to 86and must be the same on all nodes. It is not uncommon for node sections to
49be completely empty - if the default values are right. 87be completely empty - if the default values are right.
50 88
51Node-specific settings can be used at any time. If used before the first 89Node-specific settings can be used at any time. If used before the first
52node section they will set the default values for all following nodes. 90node section they will set the default values for all following nodes.
53 91
60values on different nodes using C<on>), but will affect the behaviour of 98values on different nodes using C<on>), but will affect the behaviour of
61the gvpe daemon and all connections it creates. 99the gvpe daemon and all connections it creates.
62 100
63=over 4 101=over 4
64 102
103=item chroot = path or /
104
105Tells GVPE to chroot(2) to the specified path after reading all necessary
106files, binding to sockets and running the C<if-up> script, but before
107running C<node-up> or any other scripts.
108
109The special path F</> instructs GVPE to create (and remove) an empty
110temporary directory to use as new root. This is most secure, but makes it
111impossible to use any scripts other than the C<if-up> one.
112
113=item chuid = numerical-uid
114
115=item chgid = numerical-gid
116
117These two options tell GVPE to change to the given user and/or group id
118after reading all necessary files, binding to sockets and running the
119C<if-up> script.
120
121Other scripts, such as C<node-up>, are run with the new user id or group id.
122
123=item chuser = username
124
125Alternative to C<chuid> and C<chgid>: Sets both C<chuid> and C<chgid>
126to the user and (primary) group ids of the specified user (for example,
127C<nobody>).
128
65=item dns-forw-host = hostname/ip 129=item dns-forw-host = hostname/ip
66 130
67The dns server to forward dns requests to for the DNS tunnel protocol 131The DNS server to forward DNS requests to for the DNS tunnel protocol
68(default: C<127.0.0.1>, changing it is highly recommended). 132(default: C<127.0.0.1>, changing it is highly recommended).
69 133
70=item dns-forw-port = port-number 134=item dns-forw-port = port-number
71 135
72The port where the C<dns-forw-host> is to be contacted (default: C<53>, 136The port where the C<dns-forw-host> is to be contacted (default: C<53>,
73which is fine in most cases). 137which is fine in most cases).
74 138
139=item dns-case-preserving = yes|true|on | no|false|off
140
141Sets whether the DNS transport forwarding server preserves case (DNS
142servers have to, but some access systems are even more broken than others)
143(default: true).
144
145Normally, when the forwarding server changes the case of domain names then
146GVPE will automatically set this to false.
147
148=item dns-max-outstanding = integer-number-of-requests
149
150The maximum number of outstanding DNS transport requests
151(default: C<100>). GVPE will never issue more requests then the given
152limit without receiving replies. In heavily overloaded situations it might
153help to set this to a low number (e.g. C<3> or even C<1>) to limit the
154number of parallel requests.
155
156The default should be working OK for most links.
157
158=item dns-overlap-factor = float
159
160The DNS transport uses the minimum request latency (B<min_latency>) seen
161during a connection as it's timing base. This factor (default: C<0.5>,
162must be > 0) is multiplied by B<min_latency> to get the maximum sending
163rate (= minimum send interval), i.e. a factor of C<1> means that a new
164request might be generated every B<min_latency> seconds, which means on
165average there should only ever be one outstanding request. A factor of
166C<0.5> means that GVPE will send requests twice as often as the minimum
167latency measured.
168
169For congested or picky DNS forwarders you could use a value nearer to or
170exceeding C<1>.
171
172The default should be working OK for most links.
173
174=item dns-send-interval = send-interval-in-seconds
175
176The minimum send interval (= maximum rate) that the DNS transport will
177use to send new DNS requests. GVPE will not exceed this rate even when
178the latency is very low. The default is C<0.01>, which means GVPE will
179not send more than 100 DNS requests per connection per second. For
180high-bandwidth links you could go lower, e.g. to C<0.001> or so. For
181congested or rate-limited links, you might want to go higher, say C<0.1>,
182C<0.2> or even higher.
183
184The default should be working OK for most links.
185
186=item dns-timeout-factor = float
187
188Factor to multiply the C<min_latency> (see C<dns-overlap-factor>) by to
189get request timeouts. The default of C<8> means that the DNS transport
190will resend the request when no reply has been received for longer than
191eight times the minimum (= expected) latency, assuming the request or
192reply has been lost.
193
194For congested links a higher value might be necessary (e.g. C<30>). If
195the link is very stable lower values (e.g. C<2>) might work
196nicely. Values near or below C<1> makes no sense whatsoever.
197
198The default should be working OK for most links but will result in low
199throughput if packet loss is high.
200
75=item if-up = relative-or-absolute-path 201=item if-up = relative-or-absolute-path
76 202
77Sets the path of a script that should be called immediately after the 203Sets the path of a script that should be called immediately after the
78network interface is initialized (but not neccessarily up). The following 204network interface is initialized (but not necessarily up). The following
79environment variables are passed to it (the values are just examples): 205environment variables are passed to it (the values are just examples).
206
207Variables that have the same value on all nodes:
80 208
81=over 4 209=over 4
82 210
83=item CONFBASE=/etc/gvpe 211=item CONFBASE=/etc/gvpe
84 212
85The configuration base directory. 213The configuration base directory.
86 214
87=item IFNAME=vpn0 215=item IFNAME=vpn0
88 216
89The interface to initialize. 217The network interface to initialize.
218
219=item IFTYPE=native # or tincd
220
221=item IFSUBTYPE=linux # or freebsd, darwin etc..
222
223The interface type (C<native> or C<tincd>) and the subtype (usually the
224OS name in lowercase) that this GVPE was configured for. Can be used to
225select the correct syntax to use for network-related commands.
90 226
91=item MTU=1436 227=item MTU=1436
92 228
93The MTU to set the interface to. You can use lower values (if done 229The MTU to set the interface to. You can use lower values (if done
94consistently on all hosts), but this is usually ineffective. 230consistently on all nodes), but this is usually either inefficient or
231simply ineffective.
232
233=item NODES=5
234
235The number of nodes in this GVPE network.
236
237=back
238
239Variables that are node-specific and with values pertaining to the node
240running this GVPE:
241
242=over 4
243
244=item IFUPDATA=string
245
246The value of the configuration directive C<if-up-data>.
95 247
96=item MAC=fe:fd:80:00:00:01 248=item MAC=fe:fd:80:00:00:01
97 249
98The MAC address to set the interface to. The script *must* set the 250The MAC address the network interface has to use.
99interface MAC to this value. You will most likely use one of these:
100 251
101 ip link set $IFNAME address $MAC mtu $MTU up # GNU/Linux 252Might be used to initialize interfaces on platforms where GVPE does not
102 ifconfig $IFNAME ether $MAC mtu $MTU up # FreeBSD 253do this automatically. Please see the C<gvpe.osdep(5)> man page for
103 254platform-specific information.
104Please see the C<gvpe.osdep(5)> manpage for platform-specific information.
105
106=item IFTYPE=native # or tincd
107
108=item IFSUBTYPE=linux # or freebsd, darwin etc..
109
110The interface type (C<native> or C<tincd>) and the subtype (usually the os
111name in lowercase) that this gvpe was configured for. Can be used to select
112the correct syntax to use for network-related commands.
113 255
114=item NODENAME=branch1 256=item NODENAME=branch1
115 257
116The nickname of the current node, as passed to the gvpe daemon. 258The nickname of the node.
117 259
118=item NODEID=1 260=item NODEID=1
119 261
120The numerical node id of the current node. The first node mentioned in the 262The numerical node ID of the node running this instance of GVPE. The first
121config file gets ID 1, the second ID 2 and so on. 263node mentioned in the config file gets ID 1, the second ID 2 and so on.
122 264
123=back 265=back
124 266
267In addition, all node-specific variables (except C<NODEID>) will be
268available with a postfix of C<_nodeid>, which contains the value for that
269node, e.g. the C<MAC_1> variable contains the MAC address of node #1, while
270the C<NODENAME_22> variable contains the name of node #22.
271
125Here is a simple if-up script: 272Here is a simple if-up script:
126 273
127 #!/bin/sh 274 #!/bin/sh
128 ip link set $IFNAME address $MAC mtu $MTU up 275 ip link set $IFNAME up
129 [ $NODENAME = branch1 ] && ip addr add 10.0.0.1 dev $IFNAME 276 [ $NODENAME = branch1 ] && ip addr add 10.0.0.1 dev $IFNAME
130 [ $NODENAME = branch2 ] && ip addr add 10.1.0.1 dev $IFNAME 277 [ $NODENAME = branch2 ] && ip addr add 10.1.0.1 dev $IFNAME
131 ip route add 10.0.0.0/8 dev $IFNAME 278 ip route add 10.0.0.0/8 dev $IFNAME
132 279
133More complicated examples (using routing to reduce arp traffic) can be 280More complicated examples (using routing to reduce ARP traffic) can be
134found in the etc/ subdirectory of the distribution. 281found in the F<etc/> subdirectory of the distribution.
135 282
136=item ifname = devname 283=item ifname = devname
137 284
138Sets the tun interface name to the given name. The default is OS-specific 285Sets the tun interface name to the given name. The default is OS-specific
139and most probably something like C<tun0>. 286and most probably something like C<tun0>.
148device. 295device.
149 296
150=item ip-proto = numerical-ip-protocol 297=item ip-proto = numerical-ip-protocol
151 298
152Sets the protocol number to be used for the rawip protocol. This is a 299Sets the protocol number to be used for the rawip protocol. This is a
153global option because all hosts must use the same protocol, and since 300global option because all nodes must use the same protocol, and since
154there are no port numbers, you cannot easily run more than one gvpe 301there are no port numbers, you cannot easily run more than one gvpe
155instance using the same protocol, nor can you share the protocol with 302instance using the same protocol, nor can you share the protocol with
156other programs. 303other programs.
157 304
158The default is 47 (GRE), which has a good chance of tunneling through 305The default is 47 (GRE), which has a good chance of tunneling
159firewalls (but note that the rawip protocol is not GRE compatible). Other 306through firewalls (but note that gvpe's rawip protocol is not GRE
160common choices are 50 (IPSEC, ESP), 51 (IPSEC, AH), 4 (IPIP tunnels) or 98 307compatible). Other common choices are 50 (IPSEC, ESP), 51 (IPSEC, AH), 4
161(ENCAP, rfc1241) 308(IPIP tunnels) or 98 (ENCAP, rfc1241).
309
310Many versions of Linux seem to have a bug that causes them to reorder
311packets for some ip protocols (GRE, ESP) but not for others (AH), so
312choose wisely (that is, use 51, AH).
162 313
163=item http-proxy-host = hostname/ip 314=item http-proxy-host = hostname/ip
164 315
165The C<http-proxy-*> family of options are only available if gvpe was 316The C<http-proxy-*> family of options are only available if gvpe was
166compiled with the C<--enable-http-proxy> option and enable tunneling of 317compiled with the C<--enable-http-proxy> option and enable tunneling of
169C<http-proxy-host> and C<http-proxy-port> should specify the hostname and 320C<http-proxy-host> and C<http-proxy-port> should specify the hostname and
170port number of the proxy server. See C<http-proxy-loginpw> if your proxy 321port number of the proxy server. See C<http-proxy-loginpw> if your proxy
171requires authentication. 322requires authentication.
172 323
173Please note that gvpe will still try to resolve all hostnames in the 324Please note that gvpe will still try to resolve all hostnames in the
174configuration file, so if you are behind a proxy without access to a dns 325configuration file, so if you are behind a proxy without access to a DNS
175server better use numerical IP addresses. 326server better use numerical IP addresses.
176 327
177To make best use of this option disable all protocols except tcp in your 328To make best use of this option disable all protocols except TCP in your
178config file and make sure your routers (or all other hosts) are listening 329config file and make sure your routers (or all other nodes) are listening
179on a port that the proxy allows (443, https, is a common choice). 330on a port that the proxy allows (443, https, is a common choice).
180 331
181If you have a router, connecting to it will suffice. Otherwise tcp must be 332If you have a router, connecting to it will suffice. Otherwise TCP must be
182enabled on all hosts. 333enabled on all nodes.
183 334
184Example: 335Example:
185 336
186 http-proxy-host = proxy.example.com 337 http-proxy-host = proxy.example.com
187 http-proxy-port = 3128 # 8080 is another common choice 338 http-proxy-port = 3128 # 8080 is another common choice
192The port where your proxy server listens. 343The port where your proxy server listens.
193 344
194=item http-proxy-auth = login:password 345=item http-proxy-auth = login:password
195 346
196The optional login and password used to authenticate to the proxy server, 347The optional login and password used to authenticate to the proxy server,
197seperated by a literal colon (C<:>). Only basic authentication is 348separated by a literal colon (C<:>). Only basic authentication is
198currently supported. 349currently supported.
199 350
200=item keepalive = seconds 351=item keepalive = seconds
201 352
202Sets the keepalive probe interval in seconds (default: C<60>). After this 353Sets the keepalive probe interval in seconds (default: C<60>). After this
203many seconds of inactivity the daemon will start to send keepalive probe 354many seconds of inactivity the daemon will start to send keepalive probe
204every 5 seconds until it receives a reply from the other end. If no reply 355every 3 seconds until it receives a reply from the other end. If no reply
205is received within 30 seconds, the peer is considered unreachable and the 356is received within 15 seconds, the peer is considered unreachable and the
206connection is closed. 357connection is closed.
207 358
208=item loglevel = noise|trace|debug|info|notice|warn|error|critical 359=item loglevel = noise|trace|debug|info|notice|warn|error|critical
209 360
210Set the logging level. Connection established messages are logged at level 361Set the logging level. Connection established messages are logged at level
212 363
213=item mtu = bytes 364=item mtu = bytes
214 365
215Sets the maximum MTU that should be used on outgoing packets (basically 366Sets the maximum MTU that should be used on outgoing packets (basically
216the MTU of the outgoing interface) The daemon will automatically calculate 367the MTU of the outgoing interface) The daemon will automatically calculate
217maximum overhead (e.g. udp header size, encryption blocksize...) and pass 368maximum overhead (e.g. UDP header size, encryption blocksize...) and pass
218this information to the C<if-up> script. 369this information to the C<if-up> script.
219 370
220Recommended values are 1500 (ethernet), 1492 (pppoe), 1472 (pptp). 371Recommended values are 1500 (ethernet), 1492 (pppoe), 1472 (pptp).
221 372
222This value must be the minimum of the mtu values of all hosts. 373This value must be the minimum of the MTU values of all nodes.
223 374
224=item node = nickname 375=item node = nickname
225 376
226Not really a config setting but introduces a node section. The nickname is 377Not really a config setting but introduces a node section. The nickname is
227used to select the right configuration section and must be passed as an 378used to select the right configuration section and must be passed as an
228argument to the gvpe daemon. 379argument to the gvpe daemon.
229 380
230=item node-up = relative-or-absolute-path 381=item node-up = relative-or-absolute-path
231 382
232Sets a command (default: no script) that should be called whenever a 383Sets a command (default: none) that should be called whenever a connection
233connection is established (even on rekeying operations). In addition 384is established (even on rekeying operations). Note that node-up/down
385scripts will be run asynchronously, but execution is serialised, so there
386will only ever be one such script running.
387
234to the variables passed to C<if-up> scripts, the following environment 388In addition to all the variables passed to C<if-up> scripts, the following
235variables will be set: 389environment variables will be set (values are just examples):
236 390
237=over 4 391=over 4
238 392
239=item DESTNODE=branch2 393=item DESTNODE=branch2
240 394
242 396
243=item DESTID=2 397=item DESTID=2
244 398
245The node id of the remote node. 399The node id of the remote node.
246 400
401=item DESTSI=rawip/88.99.77.55:0
402
403The "socket info" of the target node, protocol dependent but usually in
404the format protocol/ip:port.
405
247=item DESTIP=188.13.66.8 406=item DESTIP=188.13.66.8
248 407
249The numerical IP address of the remote host (gvpe accepts connections from 408The numerical IP address of the remote node (gvpe accepts connections from
250everywhere, as long as the other host can authenticate itself). 409everywhere, as long as the other node can authenticate itself).
251 410
252=item DESTPORT=655 # deprecated 411=item DESTPORT=655 # deprecated
253 412
254The UDP port used by the other side. 413The protocol port used by the other side, if applicable.
255 414
256=item STATE=UP 415=item STATE=up
257 416
258Node-up scripts get called with STATE=UP, node-down scripts get called 417Node-up scripts get called with STATE=up, node-change scripts get called
259with STATE=DOWN. 418with STATE=change and node-down scripts get called with STATE=down.
260 419
261=back 420=back
262 421
263Here is a nontrivial example that uses nsupdate to update the name => ip 422Here is a nontrivial example that uses nsupdate to update the name => ip
264mapping in some dns zone: 423mapping in some DNS zone:
265 424
266 #!/bin/sh 425 #!/bin/sh
267 { 426 {
268 echo update delete $DESTNODE.lowttl.example.net. a 427 echo update delete $DESTNODE.lowttl.example.net. a
269 echo update add $DESTNODE.lowttl.example.net. 1 in a $DESTIP 428 echo update add $DESTNODE.lowttl.example.net. 1 in a $DESTIP
270 echo 429 echo
271 } | nsupdate -d -k $CONFBASE:key.example.net. 430 } | nsupdate -d -k $CONFBASE:key.example.net.
272 431
432=item node-change = relative-or-absolute-path
433
434Same as C<node-change>, but gets called whenever something about a
435connection changes (such as the source IP address).
436
273=item node-down = relative-or-absolute-path 437=item node-down = relative-or-absolute-path
274 438
275Same as C<node-up>, but gets called whenever a connection is lost. 439Same as C<node-up>, but gets called whenever a connection is lost.
276 440
277=item pid-file = path 441=item pid-file = path
286be doubled. A single C<%s> is replaced by the hostname, so you could 450be doubled. A single C<%s> is replaced by the hostname, so you could
287use paths like C<hostkeys/%s> to fetch the files at the location where 451use paths like C<hostkeys/%s> to fetch the files at the location where
288C<gvpectrl> puts them. 452C<gvpectrl> puts them.
289 453
290Since only the private key file of the current node is used and the 454Since only the private key file of the current node is used and the
291private key file should be kept secret per-host to avoid spoofings, it is 455private key file should be kept secret per-node to avoid spoofing, it is
292not recommended to use this feature. 456not recommended to use this feature.
293 457
294=item rekey = seconds 458=item rekey = seconds
295 459
296Sets the rekeying interval in seconds (default: C<3600>). Connections are 460Sets the rekeying interval in seconds (default: C<3600>). Connections are
297reestablished every C<rekey> seconds. 461reestablished every C<rekey> seconds, making them use a new encryption
462key.
463
464=item nfmark = integer
465
466This advanced option, when set to a nonzero value (default: C<0>), tries
467to set the netfilter mark (or fwmark) value on all sockets gvpe uses to
468send packets.
469
470This can be used to make gvpe use a different set of routing rules. For
471example, on GNU/Linux, the C<if-up> could set C<nfmark> to 1000 and then
472put all routing rules into table C<99> and then use an ip rule to make
473gvpe traffic avoid that routing table, in effect routing normal traffic
474via gvpe and gvpe traffic via the normal system routing tables:
475
476 ip rule add not fwmark 1000 lookup 99
298 477
299=back 478=back
300 479
301=head2 NODE SPECIFIC SETTINGS 480=head2 NODE SPECIFIC SETTINGS
302 481
303The following settings are node-specific, that is, every node can have 482The following settings are node-specific, that is, every node can have
304different settings, even within the same gvpe instance. Settings that are 483different settings, even within the same gvpe instance. Settings that are
305executed before the first node section set the defaults, settings that are 484set before the first node section set the defaults, settings that are
306executed within a node section only apply to the given node. 485set within a node section only apply to the given node.
307 486
308=over 4 487=over 4
309 488
489=item allow-direct = nodename
490
491Allow direct connections to this node. See C<deny-direct> for more info.
492
310=item compress = yes|true|on | no|false|off 493=item compress = yes|true|on | no|false|off
311 494
495For the current node, this specified whether it will accept compressed
496packets, and for all other nodes, this specifies whether to try to
312Wether to compress data packets sent to this host (default: C<yes>). 497compress data packets sent to this node (default: C<yes>). Compression is
313Compression is really cheap even on slow computers and has no size 498really cheap even on slow computers, has no size overhead at all and will
314overhead at all, so enabling this is a good idea. 499only be used when the other side supports compression, so enabling this is
500often a good idea.
315 501
316=item connect = ondemand | never | always | disabled 502=item connect = ondemand | never | always | disabled
317 503
318Sets the connect mode (default: C<always>). It can be C<always> (always 504Sets the connect mode (default: C<always>). It can be C<always> (always
319try to establish and keep a connection to the given host), C<never> 505try to establish and keep a connection to the given node), C<never>
320(never initiate a connection to the given host, but accept connections), 506(never initiate a connection to the given host, but accept connections),
321C<ondemand> (try to establish a connection on the first packet sent, and 507C<ondemand> (try to establish a connection when there are outstanding
322take it down after the keepalive interval) or C<disabled> (node is bad, 508packets in the queue and take it down after the keepalive interval) or
323don't talk to it). 509C<disabled> (node is bad, don't talk to it).
510
511Routers will automatically be forced to C<always> unless they are
512C<disabled>, to ensure all nodes can talk to each other.
513
514=item deny-direct = nodename | *
515
516Deny direct connections to the specified node (or all nodes when C<*>
517is given). Only one node can be specified, but you can use multiple
518C<allow-direct> and C<deny-direct> statements. This only makes sense in
519networks with routers, as routers are required for indirect connections.
520
521Sometimes, a node cannot reach some other nodes for reasons of network
522connectivity. For example, a node behind a firewall that only allows
523connections to/from a single other node in the network. In this case one
524should specify C<deny-direct = *> and C<allow-direct = othernodename> (the other
525node I<must> be a router for this to work).
526
527The algorithm to check whether a connection may be direct is as follows:
528
5291. Other node mentioned in an C<allow-direct>? If yes, allow the connection.
530
5312. Other node mentioned in a C<deny-direct>? If yes, deny direct connections.
532
5333. Allow the connection.
534
535That is, C<allow-direct> takes precedence over C<deny-direct>.
536
537The check is done in both directions, i.e. both nodes must allow a direct
538connection before one is attempted, so you only need to specify connect
539limitations on one node.
324 540
325=item dns-domain = domain-suffix 541=item dns-domain = domain-suffix
326 542
327The DNS domain suffix that points to the DNS tunnel server for this node. 543The DNS domain suffix that points to the DNS tunnel server for this node.
328 544
343but for the DNS tunnel protocol only. Default: C<0.0.0.0>, but that might 559but for the DNS tunnel protocol only. Default: C<0.0.0.0>, but that might
344change. 560change.
345 561
346=item dns-port = port-number 562=item dns-port = port-number
347 563
348The port to bind the DNS tunnel socket to. Must be C<0> on all DNS tunnel 564The port to bind the DNS tunnel socket to. Must be C<53> on DNS tunnel servers.
349clients and C<53> on the server.
350 565
351=item enable-dns = yes|true|on | no|false|off 566=item enable-dns = yes|true|on | no|false|off
352 567
568See gvpe.protocol(7) for a description of the DNS transport
569protocol. Avoid this protocol if you can.
570
353Enable the DNS tunneling protocol on this node, either as server 571Enable the DNS tunneling protocol on this node, either as server or as
354C<dns-port != 0> or as client C<dns-port == 0> (both at the same time is 572client. Support for this transport protocol is only available when gvpe
355not possible at the moment). 573was compiled using the C<--enable-dns> option.
574
575=item enable-icmp = yes|true|on | no|false|off
576
577See gvpe.protocol(7) for a description of the ICMP transport protocol.
578
579Enable the ICMP transport using ICMP packets of type C<icmp-type> on this
580node.
356 581
357=item enable-rawip = yes|true|on | no|false|off 582=item enable-rawip = yes|true|on | no|false|off
358 583
584See gvpe.protocol(7) for a description of the RAW IP transport protocol.
585
359Enable the RAW IPv4 transport using the C<ip-proto> protocol 586Enable the RAW IPv4 transport using the C<ip-proto> protocol
360(default: C<no>). This is the best choice, since the overhead per packet 587(default: C<no>).
361is only 38 bytes, as opposed to UDP's 58 (or TCP's 60+).
362 588
363=item enable-tcp = yes|true|on | no|false|off 589=item enable-tcp = yes|true|on | no|false|off
364 590
591See gvpe.protocol(7) for a description of the TCP transport protocol.
592
365Enable the TCPv4 transport using the C<tcp-port> port 593Enable the TCPv4 transport using the C<tcp-port> port
366(default: C<no>). Support for this horribly unsuitable protocol is only 594(default: C<no>). Support for this transport protocol is only available
367available when gvpe was compiled using the C<--enable-tcp> option. Never 595when gvpe was compiled using the C<--enable-tcp> option.
368use this transport unless you really must, it is horribly ineffiecent and
369resource-intensive compared to the other transports.
370 596
371=item enable-udp = yes|true|on | no|false|off 597=item enable-udp = yes|true|on | no|false|off
372 598
599See gvpe.protocol(7) for a description of the UDP transport protocol.
600
373Enable the UDPv4 transport using the C<udp-port> port (default: C<no>, 601Enable the UDPv4 transport using the C<udp-port> port (default: C<no>).
374unless no other protocol is enabled for a node, in which case this
375protocol is enabled automatically). This is a good general choice since
376UDP tunnels well through many firewalls.
377 602
378NOTE: Please specify C<enable-udp = yes> if you want t use it even though 603=item hostname = hostname | ip [can not be defaulted]
379it might get switched on automatically, as some future version might 604
380default to another default protocol. 605Forces the address of this node to be set to the given DNS hostname or IP
606address. It will be resolved before each connect request, so dyndns should
607work fine. If this setting is not specified and a router is available,
608then the router will be queried for the address of this node. Otherwise,
609the connection attempt will fail.
610
611Note that DNS resolving is done synchronously, pausing the daemon. If that
612is an issue you need to specify IP addresses.
613
614=item icmp-type = integer
615
616Sets the type value to be used for outgoing (and incoming) packets sent
617via the ICMP transport.
618
619The default is C<0> (which is C<echo-reply>, also known as
620"ping-reply"). Other useful values include C<8> (C<echo-request>, a.k.a.
621"ping") and C<11> (C<time-exceeded>), but any 8-bit value can be used.
622
623=item if-up-data = value
624
625The value specified using this directive will be passed to the C<if-up>
626script in the environment variable C<IFUPDATA>.
381 627
382=item inherit-tos = yes|true|on | no|false|off 628=item inherit-tos = yes|true|on | no|false|off
383 629
384Wether to inherit the TOS settings of packets sent to the tunnel when 630Whether to inherit the TOS settings of packets sent to the tunnel when
385sending packets to this node (default: C<yes>). If set to C<yes> then 631sending packets to this node (default: C<yes>). If set to C<yes> then
386outgoing tunnel packets will have the same TOS setting as the packets sent 632outgoing tunnel packets will have the same TOS setting as the packets sent
387to the tunnel device, which is usually what you want. 633to the tunnel device, which is usually what you want.
388 634
389=item max-retry = positive-number 635=item max-retry = positive-number
390 636
391The maximum interval in seconds (default: C<28800>, 8 hours) between 637The maximum interval in seconds (default: C<3600>, one hour) between
392retries to establish a connection to this node. When a connection cannot 638retries to establish a connection to this node. When a connection cannot
393be established, gvpe uses exponential backoff capped at this value. It's 639be established, gvpe uses exponential back-off capped at this value. It's
394sometimes useful to set this to a much lower value (e.g. C<120>) on 640sometimes useful to set this to a much lower value (e.g. C<120>) on
395connections to routers that usually are stable but sometimes are down, to 641connections to routers that usually are stable but sometimes are down, to
396assure quick reconnections. 642assure quick reconnections even after longer downtimes.
397 643
644=item max-ttl = seconds
645
646Expire packets that couldn't be sent after this many seconds
647(default: C<60>). Gvpe will normally queue packets for a node without an
648active connection, in the hope of establishing a connection soon. This
649value specifies the maximum lifetime a packet will stay in the queue, if a
650packet gets older, it will be thrown away.
651
652=item max-queue = positive-number>=1
653
654The maximum number of packets that will be queued (default: C<512>)
655for this node. If more packets are sent then earlier packets will be
656expired. See C<max-ttl>, above.
657
398=item router-priority = 0 | 1 | positive-number>2 658=item router-priority = 0 | 1 | positive-number>=2
399 659
400Sets the router priority of the given host (default: C<0>, disabled). If 660Sets the router priority of the given node (default: C<0>, disabled).
401some host tries to connect to another host without a hostname, it asks
402the router host for it's IP address. The router host is the one with the
403highest priority larger than C<1> that is currently reachable.
404 661
405Make sure all hosts always connect (C<connect = always>) to the router 662If some node tries to connect to another node but it doesn't have a
406hosts, otherwise connecting to them might be impossible. 663hostname, it asks a router node for it's IP address. The router node
664chosen is the one with the highest priority larger than C<1> that is
665currently reachable. This is called a I<mediated> connection, as the
666connection itself will still be direct, but it uses another node to
667mediate between the two nodes.
668
669The value C<0> disables routing, that means if the node receives a packet
670not for itself it will not forward it but instead drop it.
407 671
408The special value C<1> allows other hosts to route through the router 672The special value C<1> allows other hosts to route through the router
409host, but they will never route through it by default. The value C<0> 673host, but they will never route through it by default (i.e. the config
410disables routing. The idea behind this is that some hosts can, if 674file of another node needs to specify a router priority higher than one
675to choose such a node for routing).
676
677The idea behind this is that some hosts can, if required, bump the
411required, bump the C<router-priority> setting to higher than C<1> in their 678C<router-priority> setting to higher than C<1> in their local config to
412local config to route through specific hosts. If C<router-priority> is 679route through specific hosts. If C<router-priority> is C<0>, then routing
413C<0>, then routing will be refused, so C<1> serves as a "enable, but do 680will be refused, so C<1> serves as a "enable, but do not use by default"
414not use by default" switch. 681switch.
682
683Nodes with C<router-priority> set to C<2> or higher will always be forced
684to C<connect> = C<always> (unless they are C<disabled>).
415 685
416=item tcp-port = port-number 686=item tcp-port = port-number
417 687
418Similar to C<udp-port> (default: C<655>), but sets the TCP port number. 688Similar to C<udp-port> (default: C<655>), but sets the TCP port number.
419 689
428 698
429The default (or recommended) directory layout for the config directory is: 699The default (or recommended) directory layout for the config directory is:
430 700
431=over 4 701=over 4
432 702
433=item X<gvpe.conf> 703=item gvpe.conf
434 704
435The config file. 705The config file.
436 706
437=item X<if-up> 707=item if-up
438 708
439The if-up script 709The if-up script
440 710
441=item X<node-up>, X<node-down> 711=item node-up, node-down
442 712
443If used the node up or node-down scripts. 713If used the node up or node-down scripts.
444 714
445=item X<hostkey> 715=item hostkey
446 716
447The private key (taken from C<hostkeys/nodename>) of the current host. 717The private key (taken from C<hostkeys/nodename>) of the current host.
448 718
449=item X<pubkey/nodename> 719=item pubkey/nodename
450 720
451The public keys of the other nodes, one file per node. 721The public keys of the other nodes, one file per node.
452 722
453=back 723=back
454 724
456 726
457gvpe(5), gvpe(8), gvpectrl(8). 727gvpe(5), gvpe(8), gvpectrl(8).
458 728
459=head1 AUTHOR 729=head1 AUTHOR
460 730
461Marc Lehmann <gvpe@plan9.de> 731Marc Lehmann <gvpe@schmorp.de>
462 732

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