.B .noip
in the calling user's home directory, as determined by the
.B HOME
-environment, or, failing that, looking up the
-.I real
-(not effective) user id in the password database. However, if the
-environment variable
+environment, or, failing that, looking up the effective user id in the
+password database. However, if the environment variable
.B NOIP_CONFIG
is set, then the file it names is read instead (assuming it exists; if
it doesn't, no configuration is read).
.B NOIP_SOCKETDIR
can also be used to control which directory is used for sockets.
.TP
+.BI "autoports " min "\-" max
+Select which ports are used for implicit binding. Allocating ports can
+be a bit slow, since checking whether a Unix domain socket is in use is
+difficult. A wide range makes things easier, because
+.B noip
+starts by trying ports at random from the given range. The environment
+variable
+.B NOIP_AUTOPORTS
+can also be used to control which ports are assigned automatically.
+.TP
.BI "realbind " acl-entry
Add an entry to the
.B realbind
For example, it may be useful to allow access at least to a DNS server.
This can be accomplished by adding a line
.VS
-realconnect +1.2.3.4:52
+realconnect +1.2.3.4:53
.VE
to the configuration file, where 1.2.3.4 is the IP address of one of
your DNS server.
is implemented as an
.B LD_PRELOAD
hack. It won't work on setuid programs. Also, perhaps more
-importantly, it can't do anything a
+importantly, it can't do anything to prevent a
.I malicious
-program use of networking: a program could theoretically issue sockets
+program's use of networking: a program could theoretically issue sockets
system calls directly instead of using the C library calls that
.B noip
intercepts. It is intended only as a tool for enhancing the security of
.PP
This manual is surprisingly long and complicated for such a simple hack.
.SH AUTHOR
-Mark Wooding, <mdw@nsict.org>
+Mark Wooding, <mdw@distorted.org.uk>