finalise 2.1.2

[authbind.git] / authbind.1

diff --git a/authbind.1 b/authbind.1
index 092289d5fdd1740711cc10db5172444f92a2bbb7..d73e998990a92e6139d5c2ef6165f7aaac8e0569 100644 (file)
--- a/authbind.1
+++ b/authbind.1
@@ -17,8 +17,6 @@
 .\" along with this program; if not, write to the Free Software Foundation,
 .\" Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 
 .\"
 .\" along with this program; if not, write to the Free Software Foundation,
 .\" Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 
 .\"

-.\" $Id$
-.\"

 .TH AUTHBIND 1 "30th August 1998" "Debian Project" "Debian Linux manual"
 .SH NAME 
 authbind \- bind sockets to privileged ports without root
 .TH AUTHBIND 1 "30th August 1998" "Debian Project" "Debian Linux manual"
 .SH NAME 
 authbind \- bind sockets to privileged ports without root


@@ -88,12 +86,25 @@ Secondly, if that test fails to resolve the matter,
 (any protocol) or failing that
 .BI /etc/authbind/byaddr/ addr : port
 (IPv4 only)
 (any protocol) or failing that
 .BI /etc/authbind/byaddr/ addr : port
 (IPv4 only)

-is tested, in the same manner as above.  (Here
+is tested, in the same manner as above.  Here

 .I addr
 is as from
 .I addr
 is as from

-.BR inet_ntop .)
+.BR inet_ntop ,
+and
+.I port
+is the (local) TCP or UDP port number, expressed as an unsigned
+integer in the minimal non-zero number of digits.
+.PP
+Thirdly, for IPv6 only: since the textual representation from
+.B inet_ntop
+is complicated to predict, a variant of
+.I addr
+is also tested which does not use the double colon abbreviation:
+each 16-byte chunk expressed in the minimal nonzero number
+of hex digits (i.e. with leading zeroes removed), the chunks
+being separated by colons as is conventional.

 .PP
 .PP

-Thirdly, if the question is still unresolved, the file
+Fourthly, if the question is still unresolved, the file

 .BI /etc/authbind/byuid/ uid
 will be opened and read.  If the file does not exist then the binding
 is not authorised and
 .BI /etc/authbind/byuid/ uid
 will be opened and read.  If the file does not exist then the binding
 is not authorised and


@@ -103,21 +114,23 @@ will return
 .RI ( "Operation not permitted" ", or " "Not owner" ).
 If the file does exist it will be searched for a line of the form
 .nf
 .RI ( "Operation not permitted" ", or " "Not owner" ).
 If the file does exist it will be searched for a line of the form
 .nf

-.IR            addrmin [\fB\-\fR addrmax ]\fB,\fR portmin \fB\-\fR portmax
+.IR            addrmin [\fB\-\fR addrmax ]\fB,\fR portmin [\fB\-\fR portmax ]
+.IR            addr [\fB/\fR length ]\fB,\fR portmin [\fB\-\fR portmax ]

 .IB            addr4 / length : portmin , portmax
 .fi
 matching the request.
 The first form requires that the address lies in the
 relevant range (inclusive at both ends).
 .IB            addr4 / length : portmin , portmax
 .fi
 matching the request.
 The first form requires that the address lies in the
 relevant range (inclusive at both ends).

-The second form requires that the initial
+The second and third forms require that the initial

 .I length
 bits of
 .I addr
 match those in the proposed
 .B bind
 .I length
 bits of
 .I addr
 match those in the proposed
 .B bind

-call and is only available for IPv4.
-Addresses can
-be in any form acceptable to inet_pton.  In both cases
+call.  The third form is only available for IPv4 since IPv6 addresses
+contain colons.
+Addresses in the byuid file can
+be in any form acceptable to inet_pton.  In all cases

 the proposed port number must lie is in the inclusive range
 specified.  If such a line is found then the binding is authorised.
 Otherwise it is not, and
 the proposed port number must lie is in the inclusive range
 specified.  If such a line is found then the binding is authorised.
 Otherwise it is not, and


@@ -126,12 +139,6 @@ will fail with
 .B ENOENT
 .RI ( "No such file or directory" ).
 .PP
 .B ENOENT
 .RI ( "No such file or directory" ).
 .PP

-In each case above,
-.TP
-.I port
-is the (local) TCP or UDP port number, expressed as an unsigned
-integer in the minimal non-zero number of digits, and
-.PP

 If a read error occurs, or the directory
 .B /etc/authbind
 cannot be accessed, then not only will
 If a read error occurs, or the directory
 .B /etc/authbind
 cannot be accessed, then not only will


@@ -139,21 +146,47 @@ cannot be accessed, then not only will
 fail, but an error message will be printed to stderr.  Unrecognised
 lines in
 .BI /etc/authbind/byuid/ uid
 fail, but an error message will be printed to stderr.  Unrecognised
 lines in
 .BI /etc/authbind/byuid/ uid

-files are silently ignored (as are lines whose
-.I addr4
+files are silently ignored, as are lines whose
+.I addr

 has non-zero bits more than
 .I length
 has non-zero bits more than
 .I length

-from the top) or where
+from the top or where some

 .I min
 is larger than
 .IR max .
 .I min
 is larger than
 .IR max .

-.PP
+.SH EXAMPLE
+So for example an attempt by uid 432
+to bind to port 80 of address [2620:106:e002:f00f::21]
+would result in authbind calling
+.I access(2)
+on, in order,
+.RS
+.B /etc/authbind/byport/80
+.br
+.B /etc/authbind/byaddr/2620:106:e002:f00f::21,80
+.br
+.B /etc/authbind/byaddr/2620:106:e002:f00f:0:0:0:21,80
+.RE
+If none of these files exist, authbind will read
+.RS
+.B /etc/authbind/byuid/432
+.RE
+and search for a line to permit
+the relevant access; examples of lines which would do so are:
+.RS
+.B 2620:106:e002:f00f::21,80
+.br
+.B ::/0,80
+.RE
+.SH PORTS 512-1023

 Authorising binding to ports from 512 to 1023 inclusive is
 not recommended.  Some protocols (including some versions of NFS)
 authorise clients by seeing that they are using a port number in this
 range.  So by authorising a program to be a server for such a port,
 you are also authorising it to impersonate the whole host for those
 Authorising binding to ports from 512 to 1023 inclusive is
 not recommended.  Some protocols (including some versions of NFS)
 authorise clients by seeing that they are using a port number in this
 range.  So by authorising a program to be a server for such a port,
 you are also authorising it to impersonate the whole host for those

-protocols.  To make sure that this isn't done by accident,
+protocols.
+
+To make sure that this isn't done by accident,

 if the port number requested is in the range 512-1023, authbind
 will expect the permission files to have an additional
 .B !
 if the port number requested is in the range 512-1023, authbind
 will expect the permission files to have an additional
 .B !


@@ -317,7 +350,7 @@ was specified.
 .SH AUTHOR
 .B authbind
 and this manpage were written by Ian Jackson.  They are
 .SH AUTHOR
 .B authbind
 and this manpage were written by Ian Jackson.  They are

-Copyright (C)1998
+Copyright (C)1998,2012

 by him and released under the GNU General Public Licence; there is NO
 WARRANTY.  See
 .B /usr/doc/authbind/copyright
 by him and released under the GNU General Public Licence; there is NO
 WARRANTY.  See
 .B /usr/doc/authbind/copyright