Technical data

B. Appendixes to optional packages
#
# Expression: outbound and not icmp[0] != 8 and not tcp[13] & 4 != 0
#
(000) ldb [0]
(001) jeq #0x0 jt 17 jf 2
(002) ldh [2]
(003) jeq #0x21 jt 4 jf 18
(004) ldb [13]
(005) jeq #0x1 jt 6 jf 11
(006) ldh [10]
(007) jset #0x1fff jt 18 jf 8
(008) ldxb 4*([4]&0xf)
(009) ldb [x + 4]
(010) jeq #0x8 jt 18 jf 17
(011) jeq #0x6 jt 12 jf 18
(012) ldh [10]
(013) jset #0x1fff jt 18 jf 14
(014) ldxb 4*([4]&0xf)
(015) ldb [x + 17]
(016) jset #0x4 jt 17 jf 18
(017) ret #0
(018) ret #4
B.3. DYNDNS
B.3.1. Adding Of New Providers
Adding new providers is easy because update-scripts are separated from provider data com-
pletely. For a new provider adapt the following files:
opt/etc/dyndns/provider.NAME
This file defines how an update is working with this provider. It mostly consists only of a list
of variables but is a normal shell script that even allows complex operations to be done. This
should not be necessary in most cases. These variables can be used in the file:
$ip The IP of the interface that should get the dynamic hostname.
$host The complete hostname the user specified in his configuration.
$subdom All components of the hostname ending with the dot next to last
(name.provider.dom)
$domain the both last components of the hostname (name.provider.dom)
$provider The symbolic name of the provider the user specified in his configuration file.
$user The username for this service.
$pass The password.
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