The code in this directory derives from an old version (91) of
the ISC export library shipped with BIND9.  Most of the code in that
library was not needed and has been discarded.

It now defines a largish number of small convenience functions for working
with sockets, and one non-trivial piece of machinery; iteration over
the system's list of active TCP/IP sockets. This functionality is not
standardized by POSIX, so here we provide a wrapper around three different
platform-specific APIs:

* The getifaddrs(3) library used on Linux and some *BSDs
* The SIOCGLIFCONF ioctl used on Solaris and SunOS.
* The sysctl() kernel call implemented on some BSDs.

There are a few other entry points supporting cryptographic hashing,
assertions, and error backtraces.
