ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/gvpe/doc/gvpe.conf.5.pod
(Generate patch)

Comparing gvpe/doc/gvpe.conf.5.pod (file contents):
Revision 1.6 by pcg, Sun Mar 6 18:34:46 2005 UTC vs.
Revision 1.33 by root, Thu Jul 18 13:35:19 2013 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 following directives:
37
38=over 4
39
40=item node nodename
41
42Introduces a node section. The nodename is used to select the right
43configuration section and is the same string as is passed as an argument
44to the gvpe daemon.
45
46Multiple C<node> statements with the same node name are supported and will
47be merged together.
48
49=item global
50
51This statement switches back to the global section, which is mainly
52useful if you want to include a second config file, e..g for local
53customisations. To do that, simply include this at the very end of your
54config file:
55
56 global
57 include local.conf
58
59=item on nodename ...
60
61=item on !nodename ...
62
63You can prefix any configuration directive with C<on> and a nodename. GVPE
64will will only "execute" it on the named node, or (if the nodename starts
65with C<!>) on all nodes except the named one.
66
67Example: set the MTU to C<1450> everywhere, C<loglevel> to C<noise> on
68C<branch1>, and C<connect> to C<ondemand> everywhere but on branch2.
69
70 mtu = 1450
34 on branch1 loglevel = noise 71 on branch1 loglevel = noise
35 on !branch2 connect = ondemand 72 on !branch2 connect = ondemand
36 73
37All settings are executed "in order", that is, later settings of the same 74=item include relative-or-absolute-path
38variable overwrite earlier ones. 75
76Reads the specified file (the path must not contain whitespace or C<=>
77characters) and evaluate all config directives in it as if they were
78spelled out in place of the C<include> directive.
79
80The path is a printf format string, that is, you must escape any C<%>
81by doubling it, and you can have a single C<%s> inside, which will be
82replaced by the current nodename.
83
84Relative paths are interpreted relative to the GVPE config directory.
85
86Example: include the file F<local.conf> in the config directory on every
87node.
88
89 include local.conf
90
91Example: include a file F<conf/>nodenameF<.conf>
92
93 include conf/%s.conf
94
95=back
39 96
40=head1 ANATOMY OF A CONFIG FILE 97=head1 ANATOMY OF A CONFIG FILE
41 98
42Usually, a config file starts with global settings (like the udp port to 99Usually, 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 = 100port to listen on), followed by node-specific sections that begin with a
44nickname> line. 101C<node = nickname> line.
45 102
46Every node that is part of the network must have a section that starts 103Every 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 104with 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 105and must be the same on all nodes. It is not uncommon for node sections to
49be completely empty - if the default values are right. 106be completely empty - if the default values are right.
50 107
51Node-specific settings can be used at any time. If used before the first 108Node-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. 109node section they will set the default values for all following nodes.
53 110
60values on different nodes using C<on>), but will affect the behaviour of 117values on different nodes using C<on>), but will affect the behaviour of
61the gvpe daemon and all connections it creates. 118the gvpe daemon and all connections it creates.
62 119
63=over 4 120=over 4
64 121
122=item chroot = path or /
123
124Tells GVPE to chroot(2) to the specified path after reading all necessary
125files, binding to sockets and running the C<if-up> script, but before
126running C<node-up> or any other scripts.
127
128The special path F</> instructs GVPE to create (and remove) an empty
129temporary directory to use as new root. This is most secure, but makes it
130impossible to use any scripts other than the C<if-up> one.
131
132=item chuid = numerical-uid
133
134=item chgid = numerical-gid
135
136These two options tell GVPE to change to the given user and/or group id
137after reading all necessary files, binding to sockets and running the
138C<if-up> script.
139
140Other scripts, such as C<node-up>, are run with the new user id or group id.
141
142=item chuser = username
143
144Alternative to C<chuid> and C<chgid>: Sets both C<chuid> and C<chgid>
145to the user and (primary) group ids of the specified user (for example,
146C<nobody>).
147
65=item dns-forw-host = hostname/ip 148=item dns-forw-host = hostname/ip
66 149
67The dns server to forward dns requests to for the DNS tunnel protocol 150The DNS server to forward DNS requests to for the DNS tunnel protocol
68(default: C<127.0.0.1>, changing it is highly recommended). 151(default: C<127.0.0.1>, changing it is highly recommended).
69 152
70=item dns-forw-port = port-number 153=item dns-forw-port = port-number
71 154
72The port where the C<dns-forw-host> is to be contacted (default: C<53>, 155The port where the C<dns-forw-host> is to be contacted (default: C<53>,
73which is fine in most cases). 156which is fine in most cases).
74 157
158=item dns-case-preserving = yes|true|on | no|false|off
159
160Sets whether the DNS transport forwarding server preserves case (DNS
161servers have to, but some access systems are even more broken than others)
162(default: true).
163
164Normally, when the forwarding server changes the case of domain names then
165GVPE will automatically set this to false.
166
167=item dns-max-outstanding = integer-number-of-requests
168
169The maximum number of outstanding DNS transport requests
170(default: C<100>). GVPE will never issue more requests then the given
171limit without receiving replies. In heavily overloaded situations it might
172help to set this to a low number (e.g. C<3> or even C<1>) to limit the
173number of parallel requests.
174
175The default should be working OK for most links.
176
177=item dns-overlap-factor = float
178
179The DNS transport uses the minimum request latency (B<min_latency>) seen
180during a connection as it's timing base. This factor (default: C<0.5>,
181must be > 0) is multiplied by B<min_latency> to get the maximum sending
182rate (= minimum send interval), i.e. a factor of C<1> means that a new
183request might be generated every B<min_latency> seconds, which means on
184average there should only ever be one outstanding request. A factor of
185C<0.5> means that GVPE will send requests twice as often as the minimum
186latency measured.
187
188For congested or picky DNS forwarders you could use a value nearer to or
189exceeding C<1>.
190
191The default should be working OK for most links.
192
193=item dns-send-interval = send-interval-in-seconds
194
195The minimum send interval (= maximum rate) that the DNS transport will
196use to send new DNS requests. GVPE will not exceed this rate even when
197the latency is very low. The default is C<0.01>, which means GVPE will
198not send more than 100 DNS requests per connection per second. For
199high-bandwidth links you could go lower, e.g. to C<0.001> or so. For
200congested or rate-limited links, you might want to go higher, say C<0.1>,
201C<0.2> or even higher.
202
203The default should be working OK for most links.
204
205=item dns-timeout-factor = float
206
207Factor to multiply the C<min_latency> (see C<dns-overlap-factor>) by to
208get request timeouts. The default of C<8> means that the DNS transport
209will resend the request when no reply has been received for longer than
210eight times the minimum (= expected) latency, assuming the request or
211reply has been lost.
212
213For congested links a higher value might be necessary (e.g. C<30>). If
214the link is very stable lower values (e.g. C<2>) might work
215nicely. Values near or below C<1> makes no sense whatsoever.
216
217The default should be working OK for most links but will result in low
218throughput if packet loss is high.
219
75=item if-up = relative-or-absolute-path 220=item if-up = relative-or-absolute-path
76 221
77Sets the path of a script that should be called immediately after the 222Sets the path of a script that should be called immediately after the
78network interface is initialized (but not neccessarily up). The following 223network interface is initialized (but not necessarily up). The following
79environment variables are passed to it (the values are just examples): 224environment variables are passed to it (the values are just examples).
225
226Variables that have the same value on all nodes:
80 227
81=over 4 228=over 4
82 229
83=item CONFBASE=/etc/gvpe 230=item CONFBASE=/etc/gvpe
84 231
85The configuration base directory. 232The configuration base directory.
86 233
87=item IFNAME=vpn0 234=item IFNAME=vpn0
88 235
89The interface to initialize. 236The network interface to initialize.
237
238=item IFTYPE=native # or tincd
239
240=item IFSUBTYPE=linux # or freebsd, darwin etc..
241
242The interface type (C<native> or C<tincd>) and the subtype (usually the
243OS name in lowercase) that this GVPE was configured for. Can be used to
244select the correct syntax to use for network-related commands.
90 245
91=item MTU=1436 246=item MTU=1436
92 247
93The MTU to set the interface to. You can use lower values (if done 248The MTU to set the interface to. You can use lower values (if done
94consistently on all hosts), but this is usually ineffective. 249consistently on all nodes), but this is usually either inefficient or
250simply ineffective.
251
252=item NODES=5
253
254The number of nodes in this GVPE network.
255
256=back
257
258Variables that are node-specific and with values pertaining to the node
259running this GVPE:
260
261=over 4
262
263=item IFUPDATA=string
264
265The value of the configuration directive C<if-up-data>.
95 266
96=item MAC=fe:fd:80:00:00:01 267=item MAC=fe:fd:80:00:00:01
97 268
98The MAC address to set the interface to. The script *must* set the 269The MAC address the network interface has to use.
99interface MAC to this value. You will most likely use one of these:
100 270
101 ip link set $IFNAME address $MAC mtu $MTU up # GNU/Linux 271Might be used to initialize interfaces on platforms where GVPE does not
102 ifconfig $IFNAME ether $MAC mtu $MTU up # FreeBSD 272do this automatically. Please see the C<gvpe.osdep(5)> man page for
103 273platform-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.
113 274
114=item NODENAME=branch1 275=item NODENAME=branch1
115 276
116The nickname of the current node, as passed to the gvpe daemon. 277The nickname of the node.
117 278
118=item NODEID=1 279=item NODEID=1
119 280
120The numerical node id of the current node. The first node mentioned in the 281The 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. 282node mentioned in the config file gets ID 1, the second ID 2 and so on.
122 283
123=back 284=back
124 285
286In addition, all node-specific variables (except C<NODEID>) will be
287available with a postfix of C<_nodeid>, which contains the value for that
288node, e.g. the C<MAC_1> variable contains the MAC address of node #1, while
289the C<NODENAME_22> variable contains the name of node #22.
290
125Here is a simple if-up script: 291Here is a simple if-up script:
126 292
127 #!/bin/sh 293 #!/bin/sh
128 ip link set $IFNAME address $MAC mtu $MTU up 294 ip link set $IFNAME up
129 [ $NODENAME = branch1 ] && ip addr add 10.0.0.1 dev $IFNAME 295 [ $NODENAME = branch1 ] && ip addr add 10.0.0.1 dev $IFNAME
130 [ $NODENAME = branch2 ] && ip addr add 10.1.0.1 dev $IFNAME 296 [ $NODENAME = branch2 ] && ip addr add 10.1.0.1 dev $IFNAME
131 ip route add 10.0.0.0/8 dev $IFNAME 297 ip route add 10.0.0.0/8 dev $IFNAME
132 298
133More complicated examples (using routing to reduce arp traffic) can be 299More complicated examples (using routing to reduce ARP traffic) can be
134found in the etc/ subdirectory of the distribution. 300found in the F<etc/> subdirectory of the distribution.
135 301
136=item ifname = devname 302=item ifname = devname
137 303
138Sets the tun interface name to the given name. The default is OS-specific 304Sets the tun interface name to the given name. The default is OS-specific
139and most probably something like C<tun0>. 305and most probably something like C<tun0>.
148device. 314device.
149 315
150=item ip-proto = numerical-ip-protocol 316=item ip-proto = numerical-ip-protocol
151 317
152Sets the protocol number to be used for the rawip protocol. This is a 318Sets 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 319global option because all nodes must use the same protocol, and since
154there are no port numbers, you cannot easily run more than one gvpe 320there are no port numbers, you cannot easily run more than one gvpe
155instance using the same protocol, nor can you share the protocol with 321instance using the same protocol, nor can you share the protocol with
156other programs. 322other programs.
157 323
158The default is 47 (GRE), which has a good chance of tunneling through 324The default is 47 (GRE), which has a good chance of tunneling
159firewalls (but note that the rawip protocol is not GRE compatible). Other 325through 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 326compatible). Other common choices are 50 (IPSEC, ESP), 51 (IPSEC, AH), 4
161(ENCAP, rfc1241) 327(IPIP tunnels) or 98 (ENCAP, rfc1241).
328
329Many versions of Linux seem to have a bug that causes them to reorder
330packets for some ip protocols (GRE, ESP) but not for others (AH), so
331choose wisely (that is, use 51, AH).
162 332
163=item http-proxy-host = hostname/ip 333=item http-proxy-host = hostname/ip
164 334
165The C<http-proxy-*> family of options are only available if gvpe was 335The C<http-proxy-*> family of options are only available if gvpe was
166compiled with the C<--enable-http-proxy> option and enable tunneling of 336compiled 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 339C<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 340port number of the proxy server. See C<http-proxy-loginpw> if your proxy
171requires authentication. 341requires authentication.
172 342
173Please note that gvpe will still try to resolve all hostnames in the 343Please 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 344configuration file, so if you are behind a proxy without access to a DNS
175server better use numerical IP addresses. 345server better use numerical IP addresses.
176 346
177To make best use of this option disable all protocols except tcp in your 347To 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 348config 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). 349on a port that the proxy allows (443, https, is a common choice).
180 350
181If you have a router, connecting to it will suffice. Otherwise tcp must be 351If you have a router, connecting to it will suffice. Otherwise TCP must be
182enabled on all hosts. 352enabled on all nodes.
183 353
184Example: 354Example:
185 355
186 http-proxy-host = proxy.example.com 356 http-proxy-host = proxy.example.com
187 http-proxy-port = 3128 # 8080 is another common choice 357 http-proxy-port = 3128 # 8080 is another common choice
192The port where your proxy server listens. 362The port where your proxy server listens.
193 363
194=item http-proxy-auth = login:password 364=item http-proxy-auth = login:password
195 365
196The optional login and password used to authenticate to the proxy server, 366The optional login and password used to authenticate to the proxy server,
197seperated by a literal colon (C<:>). Only basic authentication is 367separated by a literal colon (C<:>). Only basic authentication is
198currently supported. 368currently supported.
199 369
200=item keepalive = seconds 370=item keepalive = seconds
201 371
202Sets the keepalive probe interval in seconds (default: C<60>). After this 372Sets the keepalive probe interval in seconds (default: C<60>). After this
203many seconds of inactivity the daemon will start to send keepalive probe 373many 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 374every 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 375is received within 15 seconds, the peer is considered unreachable and the
206connection is closed. 376connection is closed.
207 377
208=item loglevel = noise|trace|debug|info|notice|warn|error|critical 378=item loglevel = noise|trace|debug|info|notice|warn|error|critical
209 379
210Set the logging level. Connection established messages are logged at level 380Set the logging level. Connection established messages are logged at level
212 382
213=item mtu = bytes 383=item mtu = bytes
214 384
215Sets the maximum MTU that should be used on outgoing packets (basically 385Sets the maximum MTU that should be used on outgoing packets (basically
216the MTU of the outgoing interface) The daemon will automatically calculate 386the MTU of the outgoing interface) The daemon will automatically calculate
217maximum overhead (e.g. udp header size, encryption blocksize...) and pass 387maximum overhead (e.g. UDP header size, encryption blocksize...) and pass
218this information to the C<if-up> script. 388this information to the C<if-up> script.
219 389
220Recommended values are 1500 (ethernet), 1492 (pppoe), 1472 (pptp). 390Recommended values are 1500 (ethernet), 1492 (pppoe), 1472 (pptp).
221 391
222This value must be the minimum of the mtu values of all hosts. 392This value must be the minimum of the MTU values of all nodes.
223 393
224=item node = nickname 394=item nfmark = integer
225 395
226Not really a config setting but introduces a node section. The nickname is 396This advanced option, when set to a nonzero value (default: C<0>), tries
227used to select the right configuration section and must be passed as an 397to set the netfilter mark (or fwmark) value on all sockets gvpe uses to
228argument to the gvpe daemon. 398send packets.
399
400This can be used to make gvpe use a different set of routing rules. For
401example, on GNU/Linux, the C<if-up> could set C<nfmark> to 1000 and then
402put all routing rules into table C<99> and then use an ip rule to make
403gvpe traffic avoid that routing table, in effect routing normal traffic
404via gvpe and gvpe traffic via the normal system routing tables:
405
406 ip rule add not fwmark 1000 lookup 99
229 407
230=item node-up = relative-or-absolute-path 408=item node-up = relative-or-absolute-path
231 409
232Sets a command (default: no script) that should be called whenever a 410Sets a command (default: none) that should be called whenever a connection
233connection is established (even on rekeying operations). In addition 411is established (even on rekeying operations). Note that node-up/down
412scripts will be run asynchronously, but execution is serialised, so there
413will only ever be one such script running.
414
234to the variables passed to C<if-up> scripts, the following environment 415In addition to all the variables passed to C<if-up> scripts, the following
235variables will be set: 416environment variables will be set (values are just examples):
236 417
237=over 4 418=over 4
238 419
239=item DESTNODE=branch2 420=item DESTNODE=branch2
240 421
242 423
243=item DESTID=2 424=item DESTID=2
244 425
245The node id of the remote node. 426The node id of the remote node.
246 427
428=item DESTSI=rawip/88.99.77.55:0
429
430The "socket info" of the target node, protocol dependent but usually in
431the format protocol/ip:port.
432
247=item DESTIP=188.13.66.8 433=item DESTIP=188.13.66.8
248 434
249The numerical IP address of the remote host (gvpe accepts connections from 435The numerical IP address of the remote node (gvpe accepts connections from
250everywhere, as long as the other host can authenticate itself). 436everywhere, as long as the other node can authenticate itself).
251 437
252=item DESTPORT=655 # deprecated 438=item DESTPORT=655 # deprecated
253 439
254The UDP port used by the other side. 440The protocol port used by the other side, if applicable.
255 441
256=item STATE=UP 442=item STATE=up
257 443
258Node-up scripts get called with STATE=UP, node-down scripts get called 444Node-up scripts get called with STATE=up, node-change scripts get called
259with STATE=DOWN. 445with STATE=change and node-down scripts get called with STATE=down.
260 446
261=back 447=back
262 448
263Here is a nontrivial example that uses nsupdate to update the name => ip 449Here is a nontrivial example that uses nsupdate to update the name => ip
264mapping in some dns zone: 450mapping in some DNS zone:
265 451
266 #!/bin/sh 452 #!/bin/sh
267 { 453 {
268 echo update delete $DESTNODE.lowttl.example.net. a 454 echo update delete $DESTNODE.lowttl.example.net. a
269 echo update add $DESTNODE.lowttl.example.net. 1 in a $DESTIP 455 echo update add $DESTNODE.lowttl.example.net. 1 in a $DESTIP
270 echo 456 echo
271 } | nsupdate -d -k $CONFBASE:key.example.net. 457 } | nsupdate -d -k $CONFBASE:key.example.net.
272 458
459=item node-change = relative-or-absolute-path
460
461Same as C<node-change>, but gets called whenever something about a
462connection changes (such as the source IP address).
463
273=item node-down = relative-or-absolute-path 464=item node-down = relative-or-absolute-path
274 465
275Same as C<node-up>, but gets called whenever a connection is lost. 466Same as C<node-up>, but gets called whenever a connection is lost.
276 467
277=item pid-file = path 468=item pid-file = path
278 469
279The path to the pid file to check and create 470The path to the pid file to check and create
280(default: C<LOCALSTATEDIR/run/gvpe.pid>). 471(default: C<LOCALSTATEDIR/run/gvpe.pid>). The first C<%s> is replaced by
472the nodename - any other use of C<%> must be written as C<%%>.
281 473
282=item private-key = relative-path-to-key 474=item private-key = relative-path-to-key
283 475
284Sets the path (relative to the config directory) to the private key 476Sets the path (relative to the config directory) to the private key
285(default: C<hostkey>). This is a printf format string so every C<%> must 477(default: C<hostkey>). This is a printf format string so every C<%> must
286be doubled. A single C<%s> is replaced by the hostname, so you could 478be 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 479use paths like C<hostkeys/%s> to fetch the files at the location where
288C<gvpectrl> puts them. 480C<gvpectrl> puts them.
289 481
290Since only the private key file of the current node is used and the 482Since 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 483private key file should be kept secret per-node to avoid spoofing, it is
292not recommended to use this feature. 484not recommended to use this feature.
293 485
294=item rekey = seconds 486=item rekey = seconds
295 487
296Sets the rekeying interval in seconds (default: C<3600>). Connections are 488Sets the rekeying interval in seconds (default: C<3607>). Connections are
297reestablished every C<rekey> seconds. 489reestablished every C<rekey> seconds, making them use a new encryption
490key.
491
492=item seed-device = path
493
494The random device used to initially and regularly seed the random
495number generator (default: F</dev/urandom>). Randomness is of paramount
496importance to the security of the algorithms used in gvpe.
497
498On program start and every seed-interval, gvpe will read 64 octets.
499
500Setting this path to the empty string will disable this functionality
501completely (the underlying crypto library will likely look for entropy
502sources on it's own though, so not all is lost).
503
504=item seed-interval = seconds
505
506The number of seconds between reseeds of the random number generator
507(default: C<3613>). A value of C<0> disables this regular reseeding.
298 508
299=back 509=back
300 510
301=head2 NODE SPECIFIC SETTINGS 511=head2 NODE SPECIFIC SETTINGS
302 512
303The following settings are node-specific, that is, every node can have 513The following settings are node-specific, that is, every node can have
304different settings, even within the same gvpe instance. Settings that are 514different settings, even within the same gvpe instance. Settings that are
305executed before the first node section set the defaults, settings that are 515set before the first node section set the defaults, settings that are
306executed within a node section only apply to the given node. 516set within a node section only apply to the given node.
307 517
308=over 4 518=over 4
309 519
520=item allow-direct = nodename
521
522Allow direct connections to this node. See C<deny-direct> for more info.
523
310=item compress = yes|true|on | no|false|off 524=item compress = yes|true|on | no|false|off
311 525
526For the current node, this specified whether it will accept compressed
527packets, and for all other nodes, this specifies whether to try to
312Wether to compress data packets sent to this host (default: C<yes>). 528compress data packets sent to this node (default: C<yes>). Compression is
313Compression is really cheap even on slow computers and has no size 529really cheap even on slow computers, has no size overhead at all and will
314overhead at all, so enabling this is a good idea. 530only be used when the other side supports compression, so enabling this is
531often a good idea.
315 532
316=item connect = ondemand | never | always | disabled 533=item connect = ondemand | never | always | disabled
317 534
318Sets the connect mode (default: C<always>). It can be C<always> (always 535Sets 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> 536try to establish and keep a connection to the given node), C<never>
320(never initiate a connection to the given host, but accept connections), 537(never initiate a connection to the given host, but accept connections),
321C<ondemand> (try to establish a connection on the first packet sent, and 538C<ondemand> (try to establish a connection when there are outstanding
322take it down after the keepalive interval) or C<disabled> (node is bad, 539packets in the queue and take it down after the keepalive interval) or
323don't talk to it). 540C<disabled> (node is bad, don't talk to it).
541
542Routers will automatically be forced to C<always> unless they are
543C<disabled>, to ensure all nodes can talk to each other.
544
545=item deny-direct = nodename | *
546
547Deny direct connections to the specified node (or all nodes when C<*>
548is given). Only one node can be specified, but you can use multiple
549C<allow-direct> and C<deny-direct> statements. This only makes sense in
550networks with routers, as routers are required for indirect connections.
551
552Sometimes, a node cannot reach some other nodes for reasons of network
553connectivity. For example, a node behind a firewall that only allows
554connections to/from a single other node in the network. In this case one
555should specify C<deny-direct = *> and C<allow-direct = othernodename> (the other
556node I<must> be a router for this to work).
557
558The algorithm to check whether a connection may be direct is as follows:
559
5601. Other node mentioned in an C<allow-direct>? If yes, allow the connection.
561
5622. Other node mentioned in a C<deny-direct>? If yes, deny direct connections.
563
5643. Allow the connection.
565
566That is, C<allow-direct> takes precedence over C<deny-direct>.
567
568The check is done in both directions, i.e. both nodes must allow a direct
569connection before one is attempted, so you only need to specify connect
570limitations on one node.
324 571
325=item dns-domain = domain-suffix 572=item dns-domain = domain-suffix
326 573
327The DNS domain suffix that points to the DNS tunnel server. Needs to be 574The DNS domain suffix that points to the DNS tunnel server for this node.
328set on both client and server.
329 575
330The domain must point to a NS record that points to the I<dns-hostname>, 576The domain must point to a NS record that points to the I<dns-hostname>,
331i.e. 577i.e.
332 578
333 dns-domainname = tunnel.example.net 579 dns-domainname = tunnel.example.net
344but for the DNS tunnel protocol only. Default: C<0.0.0.0>, but that might 590but for the DNS tunnel protocol only. Default: C<0.0.0.0>, but that might
345change. 591change.
346 592
347=item dns-port = port-number 593=item dns-port = port-number
348 594
349The port to bind the DNS tunnel socket to. Must be C<0> on all DNS tunnel 595The port to bind the DNS tunnel socket to. Must be C<53> on DNS tunnel servers.
350clients and C<53> on the server. 596
597=item enable-dns = yes|true|on | no|false|off
598
599See gvpe.protocol(7) for a description of the DNS transport
600protocol. Avoid this protocol if you can.
601
602Enable the DNS tunneling protocol on this node, either as server or as
603client. Support for this transport protocol is only available when gvpe
604was compiled using the C<--enable-dns> option.
605
606=item enable-icmp = yes|true|on | no|false|off
607
608See gvpe.protocol(7) for a description of the ICMP transport protocol.
609
610Enable the ICMP transport using ICMP packets of type C<icmp-type> on this
611node.
351 612
352=item enable-rawip = yes|true|on | no|false|off 613=item enable-rawip = yes|true|on | no|false|off
353 614
615See gvpe.protocol(7) for a description of the RAW IP transport protocol.
616
354Enable the RAW IPv4 transport using the C<ip-proto> protocol 617Enable the RAW IPv4 transport using the C<ip-proto> protocol
355(default: C<no>). This is the best choice, since the overhead per packet 618(default: C<no>).
356is only 38 bytes, as opposed to UDP's 58 (or TCP's 60+).
357 619
358=item enable-tcp = yes|true|on | no|false|off 620=item enable-tcp = yes|true|on | no|false|off
359 621
622See gvpe.protocol(7) for a description of the TCP transport protocol.
623
360Enable the TCPv4 transport using the C<tcp-port> port 624Enable the TCPv4 transport using the C<tcp-port> port
361(default: C<no>). Support for this horribly unsuitable protocol is only 625(default: C<no>). Support for this transport protocol is only available
362available when gvpe was compiled using the C<--enable-tcp> option. Never 626when gvpe was compiled using the C<--enable-tcp> option.
363use this transport unless you really must, it is horribly ineffiecent and
364resource-intensive compared to the other transports.
365 627
366=item enable-udp = yes|true|on | no|false|off 628=item enable-udp = yes|true|on | no|false|off
367 629
630See gvpe.protocol(7) for a description of the UDP transport protocol.
631
368Enable the UDPv4 transport using the C<udp-port> port (default: C<no>, 632Enable the UDPv4 transport using the C<udp-port> port (default: C<no>).
369unless no other protocol is enabled for a node, in which case this
370protocol is enabled automatically). This is a good general choice since
371UDP tunnels well through many firewalls.
372 633
373NOTE: Please specify C<enable-udp = yes> if you want t use it even though 634=item hostname = hostname | ip [can not be defaulted]
374it might get switched on automatically, as some future version might 635
375default to another default protocol. 636Forces the address of this node to be set to the given DNS hostname or IP
637address. It will be resolved before each connect request, so dyndns should
638work fine. If this setting is not specified and a router is available,
639then the router will be queried for the address of this node. Otherwise,
640the connection attempt will fail.
641
642Note that DNS resolving is done synchronously, pausing the daemon. If that
643is an issue you need to specify IP addresses.
644
645=item icmp-type = integer
646
647Sets the type value to be used for outgoing (and incoming) packets sent
648via the ICMP transport.
649
650The default is C<0> (which is C<echo-reply>, also known as
651"ping-reply"). Other useful values include C<8> (C<echo-request>, a.k.a.
652"ping") and C<11> (C<time-exceeded>), but any 8-bit value can be used.
653
654=item if-up-data = value
655
656The value specified using this directive will be passed to the C<if-up>
657script in the environment variable C<IFUPDATA>.
376 658
377=item inherit-tos = yes|true|on | no|false|off 659=item inherit-tos = yes|true|on | no|false|off
378 660
379Wether to inherit the TOS settings of packets sent to the tunnel when 661Whether to inherit the TOS settings of packets sent to the tunnel when
380sending packets to this node (default: C<yes>). If set to C<yes> then 662sending packets to this node (default: C<yes>). If set to C<yes> then
381outgoing tunnel packets will have the same TOS setting as the packets sent 663outgoing tunnel packets will have the same TOS setting as the packets sent
382to the tunnel device, which is usually what you want. 664to the tunnel device, which is usually what you want.
383 665
384=item max-retry = positive-number 666=item max-retry = positive-number
385 667
386The maximum interval in seconds (default: C<28800>, 8 hours) between 668The maximum interval in seconds (default: C<3600>, one hour) between
387retries to establish a connection to this node. When a connection cannot 669retries to establish a connection to this node. When a connection cannot
388be established, gvpe uses exponential backoff capped at this value. It's 670be established, gvpe uses exponential back-off capped at this value. It's
389sometimes useful to set this to a much lower value (e.g. C<120>) on 671sometimes useful to set this to a much lower value (e.g. C<120>) on
390connections to routers that usually are stable but sometimes are down, to 672connections to routers that usually are stable but sometimes are down, to
391assure quick reconnections. 673assure quick reconnections even after longer downtimes.
392 674
675=item max-ttl = seconds
676
677Expire packets that couldn't be sent after this many seconds
678(default: C<60>). Gvpe will normally queue packets for a node without an
679active connection, in the hope of establishing a connection soon. This
680value specifies the maximum lifetime a packet will stay in the queue, if a
681packet gets older, it will be thrown away.
682
683=item max-queue = positive-number>=1
684
685The maximum number of packets that will be queued (default: C<512>)
686for this node. If more packets are sent then earlier packets will be
687expired. See C<max-ttl>, above.
688
393=item router-priority = 0 | 1 | positive-number>2 689=item router-priority = 0 | 1 | positive-number>=2
394 690
395Sets the router priority of the given host (default: C<0>, disabled). If 691Sets the router priority of the given node (default: C<0>, disabled).
396some host tries to connect to another host without a hostname, it asks
397the router host for it's IP address. The router host is the one with the
398highest priority larger than C<1> that is currently reachable.
399 692
400Make sure all hosts always connect (C<connect = always>) to the router 693If some node tries to connect to another node but it doesn't have a
401hosts, otherwise connecting to them might be impossible. 694hostname, it asks a router node for it's IP address. The router node
695chosen is the one with the highest priority larger than C<1> that is
696currently reachable. This is called a I<mediated> connection, as the
697connection itself will still be direct, but it uses another node to
698mediate between the two nodes.
699
700The value C<0> disables routing, that means if the node receives a packet
701not for itself it will not forward it but instead drop it.
402 702
403The special value C<1> allows other hosts to route through the router 703The special value C<1> allows other hosts to route through the router
404host, but they will never route through it by default. The value C<0> 704host, but they will never route through it by default (i.e. the config
405disables routing. The idea behind this is that some hosts can, if 705file of another node needs to specify a router priority higher than one
706to choose such a node for routing).
707
708The idea behind this is that some hosts can, if required, bump the
406required, bump the C<router-priority> setting to higher than C<1> in their 709C<router-priority> setting to higher than C<1> in their local config to
407local config to route through specific hosts. If C<router-priority> is 710route through specific hosts. If C<router-priority> is C<0>, then routing
408C<0>, then routing will be refused, so C<1> serves as a "enable, but do 711will be refused, so C<1> serves as a "enable, but do not use by default"
409not use by default" switch. 712switch.
713
714Nodes with C<router-priority> set to C<2> or higher will always be forced
715to C<connect> = C<always> (unless they are C<disabled>).
410 716
411=item tcp-port = port-number 717=item tcp-port = port-number
412 718
413Similar to C<udp-port> (default: C<655>), but sets the TCP port number. 719Similar to C<udp-port> (default: C<655>), but sets the TCP port number.
414 720
423 729
424The default (or recommended) directory layout for the config directory is: 730The default (or recommended) directory layout for the config directory is:
425 731
426=over 4 732=over 4
427 733
428=item X<gvpe.conf> 734=item gvpe.conf
429 735
430The config file. 736The config file.
431 737
432=item X<if-up> 738=item if-up
433 739
434The if-up script 740The if-up script
435 741
436=item X<node-up>, X<node-down> 742=item node-up, node-down
437 743
438If used the node up or node-down scripts. 744If used the node up or node-down scripts.
439 745
440=item X<hostkey> 746=item hostkey
441 747
442The private key (taken from C<hostkeys/nodename>) of the current host. 748The (default path of the) private key of the current host.
443 749
444=item X<pubkey/nodename> 750=item pubkey/nodename
445 751
446The public keys of the other nodes, one file per node. 752The public keys of the other nodes, one file per node.
447 753
448=back 754=back
449 755
451 757
452gvpe(5), gvpe(8), gvpectrl(8). 758gvpe(5), gvpe(8), gvpectrl(8).
453 759
454=head1 AUTHOR 760=head1 AUTHOR
455 761
456Marc Lehmann <gvpe@plan9.de> 762Marc Lehmann <gvpe@schmorp.de>
457 763

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines