slapo-rwm.5

ldap服务器源码

Substitution escaping has been delegated to the `$' symbol, 
which is used instead of `\e' in string substitution patterns
because `\e' is already escaped by slapd's low level parsing routines;
as a consequence, regex escaping requires
two `\e' symbols, e.g. `\fB.*\e.foo\e.bar\fP' must
be written as `\fB.*\e\e.foo\e\e.bar\fP'.
.\"
.\" The symbol can be altered at will by redefining the related macro in
.\" "rewrite-int.h".
.\"
.SH "Rewrite Context"
A rewrite context is a set of rules which are applied in sequence.
The basic idea is to have an application initialize a rewrite
engine (think of Apache's mod_rewrite ...) with a set of rewrite
contexts; when string rewriting is required, one invokes the
appropriate rewrite context with the input string and obtains the
newly rewritten one if no errors occur.
.LP
Each basic server operation is associated to a rewrite context;
they are divided in two main groups: client \-> server and
server \-> client rewriting.
.LP
client -> server:
.LP
.RS
.nf
(default)            if defined and no specific context 
                     is available
bindDN               bind
searchDN             search
searchFilter         search
searchFilterAttrDN   search
compareDN            compare
compareAttrDN        compare AVA
addDN                add
addAttrDN            add AVA (DN portion of "ref" excluded)
modifyDN             modify
modifyAttrDN         modify AVA (DN portion of "ref" excluded)
referralAttrDN       add/modify DN portion of referrals
                     (default to none)
modrDN               modrdn
newSuperiorDN        modrdn
deleteDN             delete
exopPasswdDN         password modify extended operation DN
.fi
.RE
.LP
server -> client:
.LP
.RS
.nf
searchEntryDN        search (only if defined; no default;
                     acts on DN of search entries)
searchAttrDN         search AVA (only if defined; defaults
                     to searchEntryDN; acts on DN-syntax
                     attributes of search results)
matchedDN            all ops (only if applicable; defaults
                     to searchEntryDN)
referralDN           all ops (only if applicable; defaults
                     to none)
.fi
.RE
.LP
.SH "Basic Configuration Syntax"
All rewrite/remap directives start with the prefix
.BR rwm- ;
for backwards compatibility with the historical
.BR slapd-ldap (5)
and
.BR slapd-meta (5)
builtin rewrite/remap capabilities, the prefix may be omitted, 
but this practice is strongly discouraged.
.TP
.B rwm-rewriteEngine { on | off }
If `on', the requested rewriting is performed; if `off', no
rewriting takes place (an easy way to stop rewriting without
altering too much the configuration file).
.TP
.B rwm-rewriteContext <context name> "[ alias <aliased context name> ]"
<Context name> is the name that identifies the context, i.e. the name
used by the application to refer to the set of rules it contains.
It is used also to reference sub contexts in string rewriting.
A context may alias another one.
In this case the alias context contains no rule, and any reference to
it will result in accessing the aliased one.
.TP
.B rwm-rewriteRule "<regex match pattern>" "<substitution pattern>" "[ <flags> ]"
Determines how a string can be rewritten if a pattern is matched.
Examples are reported below.
.SH "Additional Configuration Syntax"
.TP
.B rwm-rewriteMap "<map type>" "<map name>" "[ <map attrs> ]"
Allows to define a map that transforms substring rewriting into
something else.
The map is referenced inside the substitution pattern of a rule.
.TP
.B rwm-rewriteParam <param name> <param value>
Sets a value with global scope, that can be dereferenced by the
command `${$paramName}'.
.TP
.B rwm-rewriteMaxPasses <number of passes> [<number of passes per rule>]
Sets the maximum number of total rewriting passes that can be
performed in a single rewrite operation (to avoid loops).
A safe default is set to 100; note that reaching this limit is still
treated as a success; recursive invocation of rules is simply 
interrupted.
The count applies to the rewriting operation as a whole, not 
to any single rule; an optional per-rule limit can be set.
This limit is overridden by setting specific per-rule limits
with the `M{n}' flag.
.SH "REWRITE CONFIGURATION EXAMPLES"
.nf
# set to `off' to disable rewriting
rwm-rewriteEngine on

# the rules the "suffixmassage" directive implies
rwm-rewriteEngine on
# all dataflow from client to server referring to DNs
rwm-rewriteContext default
rwm-rewriteRule "(.+,)?<virtualnamingcontext>$" "$1<realnamingcontext>" ":"
# empty filter rule
rwm-rewriteContext searchFilter
# all dataflow from server to client
rwm-rewriteContext searchEntryDN
rwm-rewriteRule "(.+,)?<realnamingcontext>$" "$1<virtualnamingcontext>" ":"
rwm-rewriteContext searchAttrDN alias searchEntryDN
rwm-rewriteContext matchedDN alias searchEntryDN
# misc empty rules
rwm-rewriteContext referralAttrDN
rwm-rewriteContext referralDN

# Everything defined here goes into the `default' context.
# This rule changes the naming context of anything sent
# to `dc=home,dc=net' to `dc=OpenLDAP, dc=org'

rwm-rewriteRule "(.+,)?dc=home,[ ]?dc=net$"
            "$1dc=OpenLDAP, dc=org"  ":"

# since a pretty/normalized DN does not include spaces
# after rdn separators, e.g. `,', this rule suffices:

rwm-rewriteRule "(.+,)?dc=home,dc=net$"
            "$1dc=OpenLDAP,dc=org"  ":"

# Start a new context (ends input of the previous one).
# This rule adds blanks between DN parts if not present.
rwm-rewriteContext  addBlanks
rwm-rewriteRule     "(.*),([^ ].*)" "$1, $2"

# This one eats blanks
rwm-rewriteContext  eatBlanks
rwm-rewriteRule     "(.*), (.*)" "$1,$2"

# Here control goes back to the default rewrite
# context; rules are appended to the existing ones.
# anything that gets here is piped into rule `addBlanks'
rwm-rewriteContext  default
rwm-rewriteRule     ".*" "${>addBlanks($0)}" ":"

.\" # Anything with `uid=username' is looked up in
.\" # /etc/passwd for gecos (I know it's nearly useless,
.\" # but it is there just as a guideline to implementing
.\" # custom maps).
.\" # Note the `I' flag that leaves `uid=username' in place 
.\" # if `username' does not have a valid account, and the
.\" # `:' that forces the rule to be processed exactly once.
.\" rwm-rewriteContext  uid2Gecos
.\" rwm-rewriteRule     "(.*)uid=([a-z0-9]+),(.+)"
.\"                 "$1cn=$2{xpasswd},$3"      "I:"
.\" 
.\" # Finally, in a bind, if one uses a `uid=username' DN,
.\" # it is rewritten in `cn=name surname' if possible.
.\" rwm-rewriteContext  bindDN
.\" rwm-rewriteRule     ".*" "${>addBlanks(${>uid2Gecos($0)})}" ":"
.\" 
# Rewrite the search base according to `default' rules.
rwm-rewriteContext  searchDN alias default

# Search results with OpenLDAP DN are rewritten back with
# `dc=home,dc=net' naming context, with spaces eaten.
rwm-rewriteContext  searchEntryDN
rwm-rewriteRule     "(.*[^ ],)?[ ]?dc=OpenLDAP,[ ]?dc=org$"
                "${>eatBlanks($1)}dc=home,dc=net"    ":"

# Bind with email instead of full DN: we first need
# an ldap map that turns attributes into a DN (the
# argument used when invoking the map is appended to 
# the URI and acts as the filter portion)
rwm-rewriteMap ldap attr2dn "ldap://host/dc=my,dc=org?dn?sub"

# Then we need to detect DN made up of a single email,
# e.g. `mail=[e-mail]'; note that the rule
# in case of match stops rewriting; in case of error,
# it is ignored.  In case we are mapping virtual
# to real naming contexts, we also need to rewrite
# regular DNs, because the definition of a bindDN
# rewrite context overrides the default definition.
rwm-rewriteContext bindDN
rwm-rewriteRule "^mail=[^,]+@[^,]+$" "${attr2dn($0)}" ":@I"

# This is a rather sophisticated example. It massages a
# search filter in case who performs the search has
# administrative privileges.  First we need to keep
# track of the bind DN of the incoming request, which is
# stored in a variable called `binddn' with session scope,
# and left in place to allow regular binding:
rwm-rewriteContext  bindDN
rwm-rewriteRule     ".+" "${&&binddn($0)}$0" ":"

# A search filter containing `uid=' is rewritten only
# if an appropriate DN is bound.
# To do this, in the first rule the bound DN is
# dereferenced, while the filter is decomposed in a
# prefix, in the value of the `uid=<arg>' AVA, and 
# in a suffix. A tag `<>' is appended to the DN. 
# If the DN refers to an entry in the `ou=admin' subtree, 
# the filter is rewritten OR-ing the `uid=<arg>' with
# `cn=<arg>'; otherwise it is left as is. This could be
# useful, for instance, to allow apache's auth_ldap-1.4
# module to authenticate users with both `uid' and
# `cn', but only if the request comes from a possible
# `cn=Web auth,ou=admin,dc=home,dc=net' user.
rwm-rewriteContext searchFilter
rwm-rewriteRule "(.*\e\e()uid=([a-z0-9_]+)(\e\e).*)"
  "${**binddn}<>${&prefix($1)}${&arg($2)}${&suffix($3)}"
  ":I"
rwm-rewriteRule "^[^,]+,ou=admin,dc=home,dc=net$"
  "${*prefix}|(uid=${*arg})(cn=${*arg})${*suffix}" ":@I"
rwm-rewriteRule ".*<>$" "${*prefix}uid=${*arg}${*suffix}" ":"

# This example shows how to strip unwanted DN-valued
# attribute values from a search result; the first rule
# matches DN values below "ou=People,dc=example,dc=com";
# in case of match the rewriting exits successfully.
# The second rule matches everything else and causes
# the value to be rejected.
rwm-rewriteContext searchEntryDN
rwm-rewriteRule ".+,ou=People,dc=example,dc=com$" "$0" ":@"
rwm-rewriteRule ".*" "" "#"
.fi
.SH "MAPPING EXAMPLES"
The following directives map the object class `groupOfNames' to
the object class `groupOfUniqueNames' and the attribute type
`member' to the attribute type `uniqueMember':
.LP
.RS
.nf
map objectclass groupOfNames groupOfUniqueNames
map attribute uniqueMember member
.fi
.RE
.LP
This presents a limited attribute set from the foreign
server:
.LP
.RS
.nf
map attribute cn *
map attribute sn *
map attribute manager *
map attribute description *
map attribute *
.fi
.RE
.LP
These lines map cn, sn, manager, and description to themselves, and 
any other attribute gets "removed" from the object before it is sent 
to the client (or sent up to the LDAP server).  This is obviously a 
simplistic example, but you get the point.
.SH FILES
.TP
ETCDIR/slapd.conf
default slapd configuration file
.SH SEE ALSO
.BR slapd.conf (5),
.BR slapd\-ldap (5),
.BR slapd\-meta (5),
.BR slapd\-relay (5),
.BR slapd (8),
.BR regex (7),
.BR re_format (7).
.SH AUTHOR
Pierangelo Masarati; based on back-ldap rewrite/remap features
by Howard Chu, Pierangelo Masarati.