example

[authbind.git] / authbind.1

diff --git a/authbind.1 b/authbind.1
index 52f0204f38eeb39440e50d9085749895867801b0..2cc5a7580760e953f252978c2bb0524bc899d180 100644 (file)
--- a/authbind.1
+++ b/authbind.1
@@ -89,13 +89,32 @@ Secondly, if that test fails to resolve the matter,
 is tested, in the same manner as above.  Here
 .I addr
 is as from
 is tested, in the same manner as above.  Here
 .I addr
 is as from

-.BR inet_ntop .
-Since this is not completely predictable for IPv6,
-for IPv6 a variant of
+.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
 .I addr

-is also tested which does not contain any ommitted zeroes or colons.
+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
+So for example an attempt to bind to [2620:106:e002:f00f::21]:80
+would result in authbind calling
+.I access(2)
+on
+.B /etc/authbind/byport/80
+and then
+.B /etc/authbind/byaddr/2620:106:e002:f00f::21,80
+and then
+.BR /etc/authbind/byaddr/2620:106:e002:f00f:0:0:0:21,80 .

 .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


@@ -105,21 +124,23 @@ 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


@@ -128,12 +149,6 @@ 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


@@ -142,10 +157,10 @@ 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
 lines in
 .BI /etc/authbind/byuid/ uid
 files are silently ignored (as are lines whose

-.I addr4
+.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 .