/usr/share/ettercap/etterlog.dtd is in ettercap-common 1:0.8.2-2build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | <!ELEMENT etterlog (host*)>
<!ATTLIST etterlog version CDATA #REQUIRED>
<!ATTLIST etterlog date CDATA #REQUIRED>
<!ELEMENT host (hostname?, mac?, manuf?, distance, type, fingerprint?, os?, port*)>
<!ATTLIST host ip CDATA #REQUIRED>
<!ELEMENT hostname (#PCDATA)>
<!ELEMENT mac (#PCDATA)>
<!ELEMENT manuf (#PCDATA)>
<!ELEMENT distance (#PCDATA)>
<!ELEMENT type (#PCDATA)>
<!ELEMENT fingerprint (#PCDATA)>
<!ATTLIST fingerprint type CDATA #REQUIRED>
<!ELEMENT os (#PCDATA)>
<!ATTLIST os type CDATA #REQUIRED>
<!ELEMENT port (banner?, account*)>
<!ATTLIST port proto CDATA #REQUIRED>
<!ATTLIST port addr CDATA #REQUIRED>
<!ATTLIST port service CDATA #REQUIRED>
<!ELEMENT banner (#PCDATA)>
<!ELEMENT account (user, pass, client, info?)>
<!ATTLIST account user CDATA #REQUIRED>
<!ATTLIST account failed CDATA>
<!ELEMENT user (#PCDATA)>
<!ELEMENT pass (#PCDATA)>
<!ELEMENT client (#PCDATA)>
<!ELEMENT info (#PCDATA)>
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