On 7/19/13, Asif Ali Baig <dreamhealer@hotmail.co.uk> wrote:
Hi , I was reading this on a site about host masking just thought to share if that helps out? Reference site is mention at the end. What is Hostmask? [snip]
The traditional definition of hostmask is used in the context of a ban or ignore entry, and refers to the parts of a host address that must be present, such as "*.aol.com" is a hostmask that applies to any user host pattern, as long as it ends in .aol.com; on the other hand nick!user@ipt1234.aol.com.example is in IRC protocol what is referred to as a sender prefix, and *!*@*.aol.com is an example of a prefix mask; that is a wildcard pattern based on an entire sender prefix. Just to be clear... when reference is made to "host masking"; we are generally not talking about this at all.... but in fact about /hiding/ the true hostname, by changing IRC users' hostnames to a "substitute hostname". Such as changing Nickname!username/Realname@ipt1-2-3-4.aol.com.example To Nickname!username/Realname@Nickname.users.dal.net.example That is 'host masking' doesn't have anything directly to do with a 'mask' or 'pattern'; Although the manner in which masking possibly affects features such as Banlists, Ignore lists, and Silence lists are very important. For example: If you change the user prefix, this affects IRC clients' /IGNORE functionality. When the IRC server is testing if an entry in a banlist applies to a user trying to join a channel ---- Do you test their Masked hostname against the ban, their original unmasked hostname against the ban, or Both? If there's a channel ban like *!*@1.2.3.4/24 or *!*@[fe60::]/64 Do you check the IP address of the client joining --- when their hostname doesn't reverse resolve and they're not masked? When their host doesn't reverse resolve and they ARE masked? When their host does reverse resolve and they ARE masked? When their host does reverse resolve and they are not masked? If they are not masked, because they turned it off.... does the server attempt to figure out what their masked hostname might be, and apply the channel ban or AKICK to them? E.g. do you expand matching in the opposite direction? Or perhaps you attempt to interpolate the non-masked version and add it as an 'invisible' banlist entry, at the time that a channel operator adds a masked hostname to the banlist. -- -JH