diff options
author | eivind <eivind@FreeBSD.org> | 1998-01-09 21:13:35 +0000 |
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committer | eivind <eivind@FreeBSD.org> | 1998-01-09 21:13:35 +0000 |
commit | 781f5bff105e2b341e76efe04ea322b2c9497ca8 (patch) | |
tree | 8444286dbbb89a371acf65fe1468b1a998a99e8c /lib/libalias/libalias.3 | |
parent | 97367c5e32c06125a0fe56b5f85facbb1dd625ab (diff) | |
download | FreeBSD-src-781f5bff105e2b341e76efe04ea322b2c9497ca8.zip FreeBSD-src-781f5bff105e2b341e76efe04ea322b2c9497ca8.tar.gz |
Teach libalias to work with IPFW firewalls (controlled by a flag).
Obtained from: Yes development tree (+ 10 lines of patches from
Charles Mott, original libalias author)
Diffstat (limited to 'lib/libalias/libalias.3')
-rw-r--r-- | lib/libalias/libalias.3 | 60 |
1 files changed, 52 insertions, 8 deletions
diff --git a/lib/libalias/libalias.3 b/lib/libalias/libalias.3 index 6c86232..51f3194 100644 --- a/lib/libalias/libalias.3 +++ b/lib/libalias/libalias.3 @@ -20,8 +20,10 @@ of the text. 1. Introduction 2. Initialization and Control 2.1 PacketAliasInit() - 2.2 PacketAliasSetAddress() - 2.3 PacketAliasSetMode() + 2.2 PacketAliasUninit() + 2.3 PacketAliasSetAddress() + 2.4 PacketAliasSetMode() + 2.5 PacketAliasSetFWBase() 3. Packet Handling 3.1 PacketAliasOut() 3.2 PacketAliasIn() @@ -116,7 +118,24 @@ PacketAliasSetMode(). It is mandatory that this function be called at the beginning of a program prior to any packet handling. -.Ss 2.2 PacketAliasSetAddress() +.Ss 2.2 PacketAliasUnInit() + +.Ft void +.Fn PacketAliasUnInit "void" + +This function has no argument or return +value and is used to clear any resources +attached to internal data structures. + +This functions should be called when a +program stop using the aliasing engine; +it do, among other things, clear out any +firewall holes. To provide backwards +compatibility and extra security, it is +added to the atexit() chain by +PacketAliasInit(). Calling it multiple +times is harmless. +.Ss 2.3 PacketAliasSetAddress() .Ft void .Fn PacketAliasSetAddress "struct in_addr addr" @@ -145,7 +164,7 @@ call). It is mandatory that this function be called prior to any packet handling. -.Ss 2.3 PacketAliasSetMode() +.Ss 2.4 PacketAliasSetMode() .Ft void .Fn PacketAliasSetMode "int mode" "int mask" @@ -224,7 +243,31 @@ change or remain the same between dial-ups. If this mode bit is not set, it the link table will never be reset in the event of an address change. +.It PKT_ALIAS_PUNCH_FW. +This option make libalias `punch holes' in an +ipfw based firewall for FTP/IRC DCC connections. +The holes punched are bound by from/to IP address +and port; it will not be possible to use a hole +for another connection. A hole is removed when +the connection that use it die. To cater for +unexpected death of a program using libalias (e.g +kill -9), changing the state of the flag will +clear the entire ipfw range allocated for holes. +This will also happen on the initial call to +PacketAliasSetFWBase(). This call must happen +prior to setting this flag. + .El + +.Ss 2.5 PacketAliasSetFWBase() + +.Ft void +.Fn PacketAliasSetFWBase "unsigned int base" "unsigned int num" + +Set IPFW range allocated for punching firewall holes (with the +PKT_ALIAS_PUNCH_FW flag). The range will be cleared for all rules on +initialization. + .Sh 3. Packet Handling The packet handling functions are used to modify incoming (remote->local) and outgoing @@ -295,7 +338,7 @@ protocols place addresss and port information in the encapsulated data stream which have to be modified and can account for changes in packet length. Well known examples of such protocols -are FTP and IRC. +are FTP and IRC DCC. Return codes: .Bl -hang -offset left @@ -570,9 +613,10 @@ valid, PacketAliasInternetChecksum() will return zero. .Sh 7. Authors Charles Mott (cmott@srv.net), versions 1.0 - 1.8, 2.0 - 2.4. -Eivind Eiklund (eivind@freebsd.org), versions 1.8b and 1.9. -Added IRC support as well as contributing a number of -architectural improvements. +Eivind Eklund (eivind@freebsd.org), versions 1.8b, 1.9 and +2.5. Added IRC DCC support as well as contributing a number of +architectural improvements; added the firewall bypass +for FTP/IRC DCC. .Sh 8. Acknowledgments |