Libwrap
From Wikipedia, the free encyclopedia
- The correct title of this article is libwrap. The initial letter is shown capitalized due to technical restrictions.
libwrap is a free software program library that implements generic TCP Wrapper functionality for network service daemons to use (rather than, or in addition to, their own host access control schemes).
Originally part of the tcp_wrappers package, it per default was compiled as a static archive, and is still used as such some places, for instance in Slackware Linux 10.2. However most other FOSS Unix-like distributions, such as Debian, RedHat and NetBSD, applied patches to the Makefile in order to compile it to a shared-object and generally include that as part of their base system. Some even decouple it (and testing utilities) from 'tcpd', which is then provided as an additional package.
One of the possible problems for end-user (sysadmins) to this situation is that the 'soname' is not standardized. Although it generally is libwrap.so.0.7.6 in GNU/Linux distros, and libwrap.so.2, 3 or 7 on BSD Unix systems.
To see if sshd is dynamically linked against libwrap, or has support build-in, use one (or both) of the following comments:
ldd `which sshd` | grep libwrap strings `which sshd` | grep /etc/hosts.[ad]
For inspiration on how to make GNU Autoconf tests find a working configuration, allowing for the standard build command:
./configure --with-libwrap
Maybe look for libwrap in the configure.in file from, for example, the OpenSSH, or Stunnel tarballs.
Contents |
[edit] See also
[edit] References
[edit] External links
[edit] Documentation
- OpenBSDs' tcpd.c as libwrap usage example code
- hosts_access(3), manpage at daemon-systems.org
